This is all rather a lot to be taking in so early in the morning, especially when you are the only non-native speaker of Chinese in a class of nearly fifty students, and possibly the first Westerner ever to have attempted to train as a chef in China. Most of my classmates are young Sichuanese men in their late teens or early twenties; only two of them are women. I am not just the only foreigner in the class, but the only foreigner most of my classmates have ever met. I sit at a wooden desk somewhere in the middle of the room, my notebook and pen at the ready. The desk has been carved with graffiti by previous generations of students, their names gouged into the wood with the sharp vegetable-carving knives they sell in the school shop. Several of my classmates are puffing away at cigarettes, and sit enveloped in clouds of smoke. The young bloke next to me has a lump of dough in his hand, with which he dreamily forms and reforms the same frilly dumpling as he half-listens to the teacher.

It is just before 9 a. m. in a classroom at the cooking school, and Teacher Long is explaining how to make huo bao yao hua, 'fire-exploded kidney flowers'. She draws a long flow chart on the blackboard in powdery chalk as she takes us through the various procedures of the recipe, scrawling down the technical terms in Chinese characters. It's all very systematic. The cooking method is huo bao, 'fire-exploding', a variation of basic stir-frying that involves cooking finely cut ingredients very fast over a high flame. The flavour profile is han xian wei, salty-savoury flavour. And because pig's kidneys, the main ingredient, have a distinctive 'off-taste' (yi wei), or more specifically a 'uriney taste' (sao wei) in their raw state, it is essential to marinate them in Shaoxing wine to refine and elevate their flavour.

After their initial amazement at being expected to study alongside a foreigner, or lao wai, most of my classmates have become used to me, although many of them still find the idea of actually talking to me impossibly daunting. They skirt around me as if I am some kind of freak, snigger amongst themselves when I address them, and avoid looking me in the eye. It takes weeks of good-humoured lobbying on my part before I can persuade some of them to stop calling me lao wai to my face, and to use instead my Chinese name, fu xia, or at least the more friendly term tong xue: 'classmate'.

Teacher Long outlines the te dian or 'special characteristics' of the dish: 'You must make sure,' she says, 'that the kidneys are cut attractively (yao hua xing mei guan), that they are both tender and crisp in the mouth (zhi nen cui), and that the taste is savoury and delicious (wei xian mei).' The te dian are one of the most important parts of the lesson. We never use weighing scales or measuring spoons at the cooking school except in pastry class; we have to learn how to judge with our senses when a dish looks, smells, tastes and feels right at every stage of its preparation. And despite the lingering pretence that China is a socialist country, every dish we learn at the school is firmly fixed in a class hierarchy. Some recipes might be suitable for serving among the hot dishes at an 'ordinary feast'; others to be the grand 'head dish' of a top-class banquet. 'Fire-exploded kidney flowers', however, is a relatively humble affair: 'convenient food for the masses,' says Teacher Long.

Most of the boys are from working-class or peasant homes. I make friends with one or two of them, including a rosy-faced and exuberant seventeen-year-old called Zeng Bo who breaks the ice by inviting me to his grandmother's birthday party. He is a naively devoted communist who believes the party line that the students who demonstrated in Tiananmen Square in 1989 were manipulated by 'a small handful of political renegades'. But although he is devoted to the Party and dreams of becoming a member like his father and grandfather, he is even more devoted to food. His full, round face lights up as he describes his favourite dishes; his plump, red lips murmur their praises. I find in him a kindred spirit.

Of course there are exceptions, like Wang Fang, one of the two other women in the class, who has become a particular ally. Her husband has won a scholarship to go to America for his PhD, and she wants to learn to cook so that she can pick up part-time work in restaurants when she goes over there to join him. Perhaps because of this prospect of travelling abroad, she is outward-looking and delighted to have the chance to associate with a foreigner. Right from the beginning, she treats me as a person rather than a circus animal or a Martian. But she is the only student from a relatively 'cultured' background. Our other female classmate is from a peasant household and is overcome with smiling bashfulness whenever she comes face to face with me.

While I said that enrolling at the cooking school marked the start of my apprenticeship, that's actually an anachronism, because the system of apprenticeship -- officially, at least -- is long dead. In the old days, all professional culinary wisdom was passed on orally from master to apprentice; written cookery books barely existed. When a master chef, or shi fu, needed some help in his kitchen, he took on as apprentices, or tu di, boys in their early teens, who would serve him for years in return for bed and board and a culinary education. They had to rise early to begin making doughs and chopping vegetables; stay up late into the night washing dishes. If their master was cruel, it could be a form of slavery: many apprentices were beaten and abused. Luckier ones found themselves welcomed into the bosom of their masters' families, and treated as adopted sons. Whole networks of professional kinship spread out from masters' kitchens: for the rest of their lives, chefs would speak of those who had trained with the same master as shi xiong (older brother under the same teacher) and shi di (younger brother under the same teacher).

The master-apprentice system declined during the Cultural Revolution, when haute cuisine was blacklisted and even small-time street traders were banned as capitalists. Senior chefs were persecuted, and the new doctrine of equality smashed the bond of subservience between apprentice and master. Some masters, humiliated by their students after a lifetime of respect, gave up hope in their profession, and refused to continue teaching, even when the madness of the political campaigns subsided.

The master cooks often feared that their apprentices, growing in skills and experience, would steal their secrets and become professional rivals. And so arose the tradition of liu yi shou, 'holding back a trick or two'. Talented chefs would deliberately mislead their apprentices, handing down incomplete recipes, giving erroneous instructions, or adding vital ingredients to their soups in secret. And so, according to legend, many of the greatest recipes in Chinese culinary history died out with the masters who made them. Contemporary chefs and gourmets groan when they imagine what has been lost over the centuries, and accuse the jealous old masters of dereliction in their duty to Chinese cuisine.

The creation of professional cooking academies was a valiant attempt to modernise attitudes, but echoes of the old apprentice system linger. Restaurant chefs continue to speak of their shi fus and fellow apprentices, and many people regard the old ways as superior. 'The difference between the old apprentices and modern students is like the difference between free-range and battery eggs,' one elderly gourmet told me. 'In a cooking school you can produce more chefs, more quickly, but they don't taste as good!'

In the late seventies and early eighties, when the post-Mao government started trying to pick up the pieces after the 'Decade of Chaos', there was a movement to codify and modernise Chinese cuisine. The Culinary Association of China was established, with branches all over the country, to research and promote food culture, and regional cookery books rolled off the presses. The Sichuan Institute of Higher Cuisine was founded in Chengdu in 1985: its mission to teach systematically and professionally, without the feudalistic practices of 'holding back tricks' and institutionalised slavery. Students would learn the techniques that enabled them to create their own dishes, rather than a set repertoire of recipes from a single master. My own teachers there, who themselves had been among the first graduates of the school, promised me and my fellow students that they would teach us everything they knew.

Mandarin, or Standard Chinese, was officially the language of the classroom all over China, but in practice Teacher Long, like the other teachers at the cooking school, conducted her classes in broad Sichuan dialect. After all, that's what everyone spoke in Chengdu, apart from a few people like me, and as they say in far-flung provinces like Sichuan, 'Heaven is high and the Emperor is far away'. The constant barrage of dialect was a gruelling initiation for me. Although I'd already lived in Chengdu for a year and picked up a few of its words and phrases, most Chinese people switched to Mandarin when they talked to me, so this was my first experience of total immersion. As Teacher Long scribbled in chalk on the blackboard, I struggled to keep up with the flood of unfamiliar words. She didn't write very clearly either, so the characters on the board were usually what the Chinese call 'grassy' (cao): fluid and scrawly. I had to beg my classmates to help me out, rewriting the characters in clear strokes in my notebook so I could look them up later in a dictionary. On occasion Wang Fang lent me her notes, which I would photocopy and use to catch up in my own time.

And then there are the pure dialect words, which are charming when you get to know them but initially incomprehensible: 'me dei' instead of 'mei you', meaning 'have not'; 'sa zi' instead of 'shen me' for 'what?', 'bu shao di' instead of 'wo bu zhi dao' for 'I don't know'; not to mention a whole gamut of fruity slang and swear words. Luckily, my burning curiosity about Sichuanese cookery spurred me on to retune my ears and tongue, and I learnt, fast. It didn't take long before my pure Chinese-lesson Mandarin was on the skids, and before people I met from Beijing and Shanghai were asking me why on earth I was talking with a Sichuanese accent.

Sichuanese dialect is like Mandarin put through a mangle. So the Mandarin 'sh' becomes 's', vowels are stretched out like warm toffee, there are pirate-like rolling 'r' sounds at the end of sentences, and no one can tell the difference between 'n' and 'l' or 'f' and 'h' (the province of Hunan, for example, is known in Sichuan, helpfully, as 'Fulan'). Furthermore, learning the tones of Mandarin Chinese is difficult enough to begin with: you must distinguish between the flat first tone (mā), the rising second tone (má), the dipping third tone (mǎ), and the fast-falling fourth tone (mà), not to mention the unobstrusive neutral tone (ma). If you have no sense of tones when speaking Mandarin, people won't understand you, and you may find yourself making mistakes like asking for a kiss (qǐng wěn) when you all you wanted was an answer to a question (qǐng wèn). But in Sichuanese even the standard tones are all over the place.

I was also flung headlong into a maelstrom of specialised culinary vocabulary. Professional Chinese cookery is serious, complex and sophisticated. Like the French, with their great canon of sauces, all richly differentiated, and their structured approach to the kitchen and the culinary arts, the Chinese make minute distinctions between different shapes into which ingredients may be cut, different combinations of tastes, and different kinds of braising and stir-frying. The basic word chao, for example, means 'stir-fry', but if you want to be really precise, you should specify whether you mean hua chao ('slippery stir-fry'), bao chao ('explode stir-fry'), xiao chao ('small, simple stir-fry'), sheng chao ('raw stir-fry'), shu chao ('cooked stir-fry'), chao xiang ('stir-fry until fragrant'), yan chao ('salt stir-fry'), or sha chao ('sand stir-fry'). And those are just the ones that I can remember off the top of my head.

One Sichuanese culinary encyclopaedia lists fifty-six different cooking methods currently used in Sichuan. If you go to Beijing, Guangzhou or Shanghai, you'll find countless others, some of them very local and specific. Even as far back as the second century BC, when my own Iron Age ancestors were living in thatched huts on a primitive diet of bread, meat and porridge, a burial inventory found in a Chinese aristocrat's tomb in Hunan listed more than ten different cooking and food-preserving methods, not to mention a whole variety of different cuts of meat, types of stew and seasonings. The Chinese knew how to eat well, even then.

After the morning break, we all reassemble in the demonstration room, where curved benches rise steeply in rows above the cooking station. It's like an amphitheatre where some magnificent sporting feat is about to take place. Which, in a way, it is. There's always a scramble for seats at the front, because we know by now that if you sit there you'll get the first chance at the tasting, before your greedy classmates have scraped the platter clean. The air is hot with anticipation. Teacher Long is already preparing the fu liao, the accompanying ingredients: ginger, garlic, spring onions, long scarlet pickled chillies, and wo sun, the crisp, jade-green stem of a local variety of lettuce.

Some of the characters that Teacher Long and her colleagues wrote on the board were so specialised and obscure that they were not listed in mainstream dictionaries. Even my clever, academic Chinese friends at the university couldn't help me when I was stuck with my cooking school textbook, because they didn't know the characters for 'slow-braising with a gently simmering sauce that makes a sound like gu du gu du gu du', or 'muttony odour'. I took a voracious pleasure in collecting these arcane terms, learning them like a sutra. (As a result, after my long apprenticeship in Chinese cookery, I have the most bizarre vocabulary of any foreign student of Chinese. I can write out the name of an obscure fungus or an ancient term for pork, and recognise the words for the 'silver ingot' shape of certain dumplings or the bouncy texture of a squid ball -- to the astonishment of Chinese culinary professionals -- but I couldn't tell you how to write some perfectly ordinary words like 'bank account', 'shy' or 'tennis'.)

Teacher Long peels off the thin, silken membranes of the kidneys, lays them on the chopping board and then slices them in half, her razor-sharp cleaver parallel to the board. She shaves off the pale delta of white drainage tubes, leaving clean the dark, metal-pink flesh. And then it all gets very complicated. She holds the blade at a slanting angle, and covers each kidney with surgical incisions, each one a few millimetres apart from the last, cutting about two-thirds of the way into the flesh but not all the way through, until the whole surface is covered with perfectly precise slashes. Then she turns each kidney so the cuts she has already made are at right angles to the knife, and makes more rows of cuts, close together. And here it gets even more fiddly: each perpendicular cut goes all the way through to the board for part of its length, except for every third cut, which goes all the way through for its whole length… so she ends up with trios of jagged frills of kidney, joined together at one end. 'These are called "phoenix tails" (feng wei),' she tells us. 'Of course, you can also cut them into eyebrows,' she continues, giving further, even more complicated, instructions.

When we have all quietened down, she begins to give us a detailed explanation of how to cut them. The ginger and garlic, peeled, must be cut into zhi jia pian, 'thumbnail slices', she says. Teacher Long wields the broad blade of her cleaver as delicately as a scalpel, reducing the tiny garlic cloves and peeled ginger root to a pile of thin, even slices. She cuts the onions and chillies into long diagonal slices called ma er duo, or 'horse's ears', and the lettuce stem into kuai zi tiao, 'chopstick strips'. The real technical nightmare of this dish, however, lies not in using a large cleaver to chop garlic cloves without also chopping off your fingers, but in cutting the kidneys themselves. 'Kidney flowers', the rather poetic phrase in the name of the dish, refers to the delicate way in which the kidneys are cut, so that when they are cooked in the fiery-hot oil, they curl up into delightfully frilly little morsels, and don't look like kidneys at all.

Cutting is one of the fundamental skills of the Chinese kitchen, as central to it as the application of fire and flavour. In ancient China, cooking itself was known as ge peng, 'to cut and to cook'; and every lesson for a trainee Chinese chef still involves precise instructions for exactly how everything should be chopped. This is partly because of the prevalence of fast stir-frying as a cooking method. For a stir-fry, all the ingredients must be cut into small pieces that need little more than a lick of heat to be cooked. If the pieces are too big, they will remain raw inside while their outsides become dry and 'old' (lao). If they are cut unevenly, they will all be cooked at different times, so the final result will be rough and unsatisfactory. And with really fast stir-frying methods such as bao, which literally means 'burst' or 'explode', the fine, even chopping of ingredients is even more essential. Careful cutting is not a cosmetic matter: it is integral to the success of the final dish.

Chopsticks, used in China for two, maybe even three thousand years, make their own demands. Knives are almost never seen on the Chinese dinner table, so food must be tender enough to be torn gently apart with chopsticks, or otherwise cut into bite-sized pieces. At grand feasts, you may find whole ducks, chickens or pork knuckles, braised so lovingly that they melt away at the touch of a chopstick, but for everyday meals, almost everything is finely sliced or slivered.

But these are simply the practicalities of cutting. What are even more fascinating are its aesthetic aspects. Skilful cutting adds an extra dimension to the enjoyment of a dish. Think only of a stir-fry of eel and vegetables where all the ingredients, different though they may be in colour, taste and texture, are cut into similar snaking strands; or the delicacy of intention that cuts chicken and spring-onion whites into tiny cubes to echo the small, solid shape of the peanuts in Gong Bao Chicken. Delicate cutting is part of a refined and civilised culinary culture that has existed in China for thousands of years. In the fifth century BC, Confucius himself allegedly refused to eat food that wasn't properly cut. 'Knife skills' (dao gong) are still the starting point for any aspiring chef.

The meticulous Chinese approach to cutting has spawned a highly elaborate vocabulary. Chefs speak of at least three basic ways of cutting, including vertical slicing (qie), horizontal slicing (pian) and chopping (zhan or kan). When the angle of the knife and the direction of cutting are taken into account, these multiply into at least fifteen variations, each with a different name. Another dozen or so terms refer to further knife techniques, including pounding (chui), scraping (gua) and gouging (wan).

Given the complexity of the art of cutting, you might expect the Chinese chef to have a whole armoury of fancy knives at his disposal. Nothing, however, could be further from the truth. The instrument of almost all this artistry is the simple cleaver, a hammered blade of carbon steel with a wooden handle and a well-honed edge.

There is also an extensive vocabulary, some of it quite poetic, to describe the shapes into which cooking ingredients can be cut. There are simple slices (pian), strips (tiao), chunks (kuai), small cubes (ding) and slivers (si). Each of these has many variations, depending on their precise shapes and dimensions: a slice, for example, might be a small 'thumbnail slice', a rectangular 'domino slice' or a large, ultra-thin 'ox-tongue slice'. Spring onions can be cut into 'flowers', 'fish eyes' or 'silken threads'. All this contributes greatly to the thrilling diversity of Chinese cuisine. Even an everyday ingredient such as pork can reveal so many different selves, depending on whether it is cut into sinuous slivers, tender cubes, juicy mince or gentle slices.

At breaktimes, the corridors of the cooking school were filled with young men bearing lethally sharp cleavers, dangling from their hands in the most nonchalant manner. For me, this took some getting used to. In the beginning, I retained my European view of the cleaver as a bloody, murderous knife, the kind of thing a psychopath or a triad hitman might use on a drunken rampage. It was only later that I began to appreciate it as the subtle, versatile instrument that it really is. Soon I, too, had a cleaver by my side at all times. During breaks, I sharpened it on the giant whetstone in the school yard like my classmates, keeping it keen.

The Chinese kitchen cleaver is not a butcher's knife. There are, it's true, heavy cleavers for chopping through pork ribs or the carcasses of fowl. But the everyday cleaver, the cai dao or 'vegetable knife', is unexpectedly light and dextrous, as suitable for slicing a small shallot as a great hunk of meat, and used by everyone from the most macho chef to the frailest old lady. A single cleaver can be used to perform almost every task, from chopping a lotus root to peeling a tiny piece of ginger, and it's often the only knife in a Chinese kitchen.

The cleaver is not just for cutting. Invert it and its blunt spine can be used to pound meat to a paste for meatballs: a time-consuming method, but the purée it produces is perfectly smooth and voluptuous. The nub of the handle can stand in for a pestle, to crush a few peppercorns in a pot. The flat of the blade, slammed down on the board, can be used to smash unpeeled ginger, so that its juices permeate a soup or marinade. Best of all, the flat blade can be used to scoop up whatever is on your chopping board, and transfer it to the pot or wok.

My parents gave me a set of fully-forged Sabatier kitchen knives for my twenty-first birthday, but these days, back home in London, I rarely use them. My hand-made Sichuanese knife has become my indispensable cooking tool; it's like a talisman. I bought it in a street market in Chengdu, for the equivalent of a couple of pounds, and I've been using it for years. I know its breadth and its heaviness, the exact shape of its handle, the pewter tones of its carbon-steel blade. I like to hold it in my hand, to feel its lightness and its weight, to place my palm on the flat of its blade, to hold it close to my chest. It makes me feel capable, it's a craftman's tool, dazzling in its multiplicity of uses. And it needs looking after, this knife of mine, honing on the whetstone, oiling to keep it from rust.

Cleavers, of course, are not only dangerous to those who try to cross a well-trained chef, but to the chef herself. Sharpened, they demand your full attention. If you don't cut mindfully, you may mutilate your hands. I once met a young chef who had lost the top joint of his index finger: he was working with a recently bandaged stump. In my first months in Chengdu I came close to this myself, as I was cutting a pile of candied fruits for a Christmas pudding. The knife was sticking, and dragging in the syrupy fruits. Tired, I became careless. I lost my concentration, and shaved a thick slice off the top of my finger, nail and all. It was a shocking accident, and I still bear the scar. But it reminded me to treat my cleaver with respect. Now, I understand that cutting can be a meditation, and why the great Taoist sage Zhuangzi used the tale of a chef and his knife as a metaphor for the art of living:

When I'm doing cooking demonstrations or making dinner at other people's homes I like to take it with me, wrapped in a cloth and stashed in my handbag. Many times I've travelled on the London Underground with my cleaver, or walked through a dangerous part of the city, late at night. As I wait on deserted station platforms, or make my way through a maze of tunnels, it gives me a sweet, secret pleasure to imagine what might happen if someone were fool enough to try to mug me. 'Shall we start with ox-tongue slices, or dominoes?' I might ask my assailant, blade gleaming in the half-light.

Cook Ting put down his knife and said, 'What your servant loves best is the Tao, which is better than any art. When I started to cut up oxen, what I saw was just a complete ox. After three years, I had learnt not to see the ox as a whole. Now I practise with my mind, not with my eyes. I ignore my sense and follow my spirit. I see the natural lines and my knife slides through the great hollows, follows the great cavities, using that which is already there to my advantage. Thus, I miss the great sinews and even more so, the great bones. A good cook changes his knife annually because he slices. An ordinary cook has to change his knife every month because he hacks. Now this knife of mine I have been using for nineteen years, and it has cut thousands of oxen. However, its blade is as sharp as if it had just been sharpened. Between the joints there are spaces, and the blade of a knife has no real thickness. If you put what has no thickness into spaces such as these, there is plenty of room, certainly enough for the knife to work through. However, when I come to a difficult part and can see that it will be difficult, I take care and pay due regard. I look carefully and I move with caution. Then, very gently, I move the knife until there is a parting and the flesh falls apart like a lump of earth falling to the ground. I stand with the knife in my hand looking around and then, with an air of satisfaction, I wipe the knife and put it away.'

'Ah, how excellent!' said Lord Wen Hui. 'How has your skill become so superb?'

Cook Ting was butchering an ox for Lord Wen Hui. Every movement of his hand, every shrug of his shoulder, every step of his feet, every thrust of his knee, every sound of the sundering flesh and the swoosh of the descending knife, were all in perfect accord…

I was often reminded of Cook Ting when I watched our teachers give their demonstrations in that small amphitheatre. Teacher Long, showing us how to remove the bones and innards from a duck, which she would later fill with an 'eight-treasure stuffing', tying the duck around the waist with a cord so that its flesh swelled out on either side like a calabash gourd. She would make a small incision through the neck and spine with her cleaver and then proceed to undress the raw bird, casually removing its entire skin and flesh in one piece from the carcass as she chatted, coaxing out the leg- and wing-bones, caressing its ribcage with the huge shining blade. Or, on another day, Teacher Long's husband, Teacher Lu, cutting pork slivers with an expression of discreet pleasure on his face, his arms and shoulders soft and supple, his composure complete amid the chaos of the classroom.

'Splendid!' said Lord Wen Hui. 'I have heard what Cook Ting has to say and from his words I have learned how to live life fully.'

Over time, Chinese cutting became part of my make-up, too. It began to influence the way in which I viewed the ingredients in my fridge, or assembled a European salad or a stew. Now, it is instinctive to me. I find I get confused when I'm helping a Western friend to prepare a meal. 'Can you just chop up some carrots?' they might say. 'But how do you want them cut?' I ask. 'Oh, just chop them,' they say. But in my mind there are now a thousand possibilities, there is no such thing as 'just chopping'. If I was cooking with a Chinese chef, it would be easy: he'd just say, 'Elephant-tusk strips, please', or, 'No. 2 thickness slivers,' and I'd know exactly what he meant.

Many of my classmates lived in dormitories upstairs at the cooking school, and sometimes the bolder among them would invite me up at lunchtime for a cup of tea and a game of cards or Mah Jong. Their rooms were crammed with bunk-beds, and hung with laundry. Sometimes they were used for nefarious activities, as I gathered one morning during a stern lecture by the school's principal. He admonished the students for gambling away their living allowances, and for smuggling their girlfriends in for the night. 'If you fritter away all your money at Mah Jong, you won't have anything left to eat,' he told us. And he gave his homily a Confucian slant: 'A good cook must lead a good life. Take Master Liu, a chef I know who is now eighty years old. He has never drunk or smoked, and he has always led a virtuous life. His cooking is incomparable.'

Living at the opposite end of town, near the university, I never witnessed any of these alcohol-fuelled orgies or reckless gambling sessions. After lunch, in the sleepy siesta hour, the atmosphere was rather more subdued. One afternoon, I sipped jasmine-blossom tea with a classmate as he gave me a tour of his miniature garden of carved vegetables. As his roommates snoozed or read cookery books, he showed me a painted landscape decorated with ornate pagodas made from pumpkin flesh; graceful swans fashioned out of pieces of white radish held together by toothpicks; carrot-flowers and purple-radish roses.

Chinese vegetable carving takes the art of cutting into another league. Here, the results are meant not to be eaten, but to be admired. The truly proficient Chinese chef is not merely a cook, but also a sculptor, like the French pâtissier, with his spun-silk caramel and sugar flowers. Food sculpture is the light-hearted, light-headed froth that floats at the top of the grandest culinary cultures. It is as ostentatious and utterly frivolous as the sugar-paste cathedrals designed by the nineteenth-century French master chef, Antonin Carême, who maintained that confectionary was the principal branch of architecture, itself one of the five fine arts. Vegetable carving can only exist in a society with a surplus of underpaid and underworked youths, who can be persuaded to spend hours engraving the outside of a watermelon with minutely realised scenes from a classic novel, or transforming an orange gourd into a vase carved with frilly-tailed goldfish playing at the base of a fragile water lily. Sometimes I find it fussy and ridiculous. But there is something enchanting about it, all the same.

These food tableaux have a venerable history in China. Their originator is said to have been a tenth-century Buddhist nun, Fan Zheng, who recreated a series of twenty-one paintings and poems by the eighth-century artist Wang Wei in the form of twenty-one cold dishes. Using finely cut pieces of vegetables, gourds, meats and fermented fish, she offered an edible homage to the works that had inspired her, to the wonderment of her dinner guests.

At cooking competitions in modern China, young chefs may be expected to enter a 'craft dish' alongside the dishes that display their wok techniques and pastry-making skills. 'Craft dishes' include complicated, edible tableaux that have little to do with the practical requirements of either cooking or eating. At one contest I attended, each competitor had produced an ornamental cold platter, or pin pan, in which tiny slices of multicoloured ingredients were assembled into grandiloquent collages. One of the entries depicted a pair of swallows, their wings made of sliced thousand-year-old eggs, their bodies and long forked tails composed of hundreds of slices of cucumber skin. They were flying over a variegated landscape of sliced cold meats, including purplish liver, rosy ham and pale-pink prawns.

When my classmates weren't carving their names into their desks, they were often toying with a carrot or an odd piece of radish, practising their sculpting techniques. They knew that, in their future careers, they might, on occasion, be required to produce a pumpkin dragon or an edible collage of the Great Wall of China. In the course of our regular culinary training, we had to learn about forty basic shapes into which raw ingredients could be cut, including nine different ways of cutting a spring onion alone. But this was child's play compared to the more esoteric art of vegetable carving.

So in the grand scale of things, cutting pig's kidneys into 'phoenix tails' or 'eyebrows' is fairly pedestrian. In the lecture theatre at the Sichuan Institute of Higher Cuisine, our demonstration is drawing to a close. Later, after lunch and a siesta, we will be let loose on our own sets of kidneys, which we will tear and mangle and cut into uneven pieces, before we acquire the knack of making phoenix tails. But now, after all her careful preparations, Teacher Long whips up the fire-exploded kidney flowers in a matter of seconds. The aromas of ginger, garlic and chilli rise steeply around the room. The kidney pieces curl up in the wok, and, then, for a few short seconds, I am able to admire them on the serving dish, marvelling at the way in which this clumsy offal has been transformed into the most tempting of delicacies. But then Teacher Long hands the plate over to the ravening masses. Students spill over the benches, jostle for position, thrust forward their chopsticks. There are a few whoops and slurps. And the kidneys are gone.