School dinners: It's my mango coulis, darling

Soon it will be lunchtime, but the bloody gelatine refuses to thicken. For hour after hour (though, according to the clock, it has only been 25 minutes), I have stood here, a knock-kneed skivvy in a brutal medieval kitchen, stirring this enraging, unyielding, heartbreakingly unco-operative mixture of egg yolks, caster sugar, milk, orange peel and gelatine in a kind of slow-motion frenzy. I have stirred for England. I have put in the hours. I have performed figures of eight in this ungrateful liquid, slooshed it this way, folded it that way, combed it with my trusty spatula as though grooming the saline tresses of a Botticelli mermaid, and still nothing has happened.

Gradually, I'm told, a strange intensity will steal over this recalcitrant yellow soup. It will start to emulsify, to solidify, to coagulate. I will get "the Red-Sea effect", meaning that when I draw a spoon through it, I'll have a clear view of the bowl's metallic bottom through the bifurcated waves. Whew. There is something undeniably sexy about all this, as you stand here beating and stroking and fondling and surreptitiously glancing at your watch while waiting for things to get serious. But you cannot allow such thoughts to distract your concentration. For here comes Jenny, five-foot-eleven of blonde omnicompetence, who looks at your handiwork, permits herself a tiny sigh of exasperation and goes off to find more gelatine and end your misery. The feeling of being back in the Mixed Infants class at my convent school in Wimbledon, taking one's laughably inept needlework up to be inspected and rubbished by the cruel-but-fair Miss Young, is strong indeed.

This is the frustrating but strangely edifying world of the cookery school, of which Leith's in central London is perhaps the most famous. Watchers of daytime TV cooking programmes will have a pretty intense diet of Leith's in the next eight weeks, as ITV broadcasts a 24-part fly-on-the-wall documentary about their teaching methods in 15-minute slices, on Tuesdays, Wednesdays and Thursdays.

Leith's School of Food and Wine has been running since 1975 and has evolved to such a pitch of sophistication that it now offers a prospectus of courses for umpteen different levels of competence. You can do a whole September- to-June, three-terms, total-immersion spectacular (costing pounds 9,200), or the classic two-terms Diploma in Food & Wine (pounds 6,450) which should be enough for most modern pursuers of the cordon bleu. There's a Beginner's Certificate (and an Intermediate and an Advanced), plus a three-week Basic Certificate in Practical Cookery (pounds 1,450, very much the choice of university-bound gels looking to liven up their gap year). There are courses to develop your knowledge of wine, courses on Indian Cooking, on dinner parties and cooking in ski resorts. There are even Corporate Hospitality nights, when a dozen businessmen pay pounds 60 a head to come in and be taught how to make their own three-course meal, while drowning in Cotes du Rhone and management camaraderie over the glazed duck breast and the sprauncy hors d'oeuvres ("Our souffle has failed to rise. I see this, not as a setback, but a challenge and an opportunity..."). Right down at the bottom of the scale, abysmally deep below the foundation courses and intensive evenings, there's the enthusiastic-amateur days. When I first spoke to the head beak, Caroline Waldegrave, I wasn't sure which kind would suit me. "There's a place left on the Beginner's Course," she said. "Or, perhaps, the Advanced?" Oh, please, I said, Beginner's? Don't make me laugh. I've been cooking since I left university. My recipe for Shoulder of Lamb Stuffed with Traditional English Breakfast was published in Options for Men a few years ago. My Fundador Trifle with Meringues...

"Can you," she enquired, "make pasta?"

Madam, I countered, if I need pasta, I buy it in Waitrose.

"How is your pastry-making?"

My, er, pastry?

"Beginner's class for you" she said firmly.

It's a five-day gig. You spend half the time in a ground-floor classroom having things demonstrated to you. Twenty-one students sit on tiny chairs balancing the 700-page Leith's Cookery Bible on a spindly tray, watching Eithne, a handsome Anglo- Irishwoman in the school uniform of blue check trousers, white apron, snood and tall chef's hat, as she talks you through the mysteries of filleting a sole, jointing a chicken and making shortcrust pastry. At the end of each demo, a plate of the delicious result circulates the room; everyone takes a tiny piece, as if under some punitive rationing system.

In the afternoon, we're upstairs in the kitchen, four of us to a preparation table, each table covered with a batterie de cuisine of knives, bowls and chopping boards in two colours (red for raw meat, brown for cooked stuff and vegetables). A small but Napoleonically dictatorial Suffolk Cockney sparrow called Emma talks us through the ground rules, most of which are concerned with safety.

You learn the right way to hold a knife, walk around with a knife, sharpen a knife, wash a knife, and what to do when you stab yourself with a knife. You learn rules of etiquette: how one cries "Hot pans!" when passing behind a fellow cook bearing a gallon of scalding root vegetables; how a decent cook would rather die than bang a spoon or cream whisk on the side of the bowl.

You note that they use only copper pans, that real cooks light gas rings with matches and don't mind screamingly hot pan handles. It's all dead professional, you see. All these people have worked in real kitchens, with sous-chefs and commis-chefs and craven juniors being yelled at by temperamental chaps with floppy hair. And we, too, shall soon be just as professional, won't we? Not on the evidence of the first day, we won't. Alongside my fiasco with the gelatine, we emerged with burnt fingers, charred chicken bits, frayed tempers and slammed fridge doors. But we took the results of our labours home in triumph, pointing out to our thunderstruck consorts the lightness of the orange mousse (though in fact, if you threw it at a wall, it would bounce right back and fracture your skull).

By the second lunchtime, as we wolfed our own Lemon Sole with Cucumber and dipped our profiteroles in molten chocolate, a fume of simple pride wafted through the room. You know, we told each other sheepishly, this isn't at all bad. We started to notice each other. There was Geoff, the aspirant hotelier who knew the answers to all the questions; Max, the French ex-ceramiciste; four American women (one teasingly named Julia Roberts) full of can-do enthusiasm and a passion for specificity - what kind of cheese is being grated there? What brand of chocolate is being melted? - and two young chaps called Simon and Piers whose week's induction was a Christmas gift from fond mammas; three teenage girls in their gap year; and a lady who'd won a whole Diploma course, and an Aga cooker thrown in, by coming top in a Good Housekeeping competition. Of the Sloane Rangers with which, I had been assured, the course was crammed, there was no sign. We were an awkward squad of aspiring Marcos and would-be gastronomes, determined to find out why, after all these years, one could flukily produce a quite respectable supper of lamb pasanda and rice, but still had no idea how to make gravy.

And so the week progressed, through bread and ice-cream and pate, and other dishes you never dreamt you'd be able to make (pate?); simple things like shepherd's pie; complicated things like crown of lamb; stylish constructions like smoked haddock Florentine, and brutally obvious items like melba toast (split a toasted slab of Mother's Pride in half and roast it). And we strove to follow it all, watching the reflection of Eithne's or Emma's or Jenny's deft hands in the long mirror that overhung the demonstration table. A recurring motif of the school was its fondness for mustard, which appeared in every recipe, bar the chocolate mousse, and the way all the teachers hurled handfuls of salt around. Jenny, the tall and thrillingly Joan Hunter Dunn-ish blonde, revealed a curious obsession with anchovies as she busied herself with a Caesar salad. She'd once eaten nothing else for a week, she said. She recommended throwing Roquefort cheese and caramelised pecans in among the cool leaves. This was a salad with guts.

But what I was happiest to discover was the 1,001 household hints - the chef's tips and handy shortcuts that are passed on to you like tribal wisdom. Such as: don't ever let gelatine boil, or your kitchen will pong like an abattoir (it's the horses' hooves). Warm hands are bad for making pastry but good for making bread. If it's raining outside, your egg whites will take longer to stiffen. You won't cry while slicing onions, provided you don't cut off the stalk at the bottom. Don't use a potato masher for mashed potato - use a sieve...

See what I mean? You start to sound like your Auntie Joan. What is going on, when the rock 'n' roll soundtrack in your head is supplanted by nagging advice about Skewer Management and Mother and Daughter Sauces? But the biggest delight on a cookery course is discovering the precision with which tiny details are addressed, and the passion that accompanies the smallest procedures. Yeast - real yeast, that is, the live stuff - was passed lovingly hand to hand and sniffed and discussed as though it had a personality - as if it were a Tamagotchi that just happened to smell like a brewery. These people take lemon wedges seriously, and gravy very seriously.

There are new words and phrases for things. "Cover the potatoes with water just to blipping level," said Jenny. "Arrange the chicken joint into sunbathing position," said Eithne (ie, with the wing-tip tucked behind, as if supporting a snoozing head on Blackpool Sands). "Chining", "battlementing", "radical French trim," "removing the paddywhack" - all were activities attached to a Rack of Lamb, now sadly redundant. The six stages of making bread (Mixing, Kneading, Rising, Knocking Back, Proving, Baking) had, inevitably, their own acronym, which stays immovably in your head for weeks ("Mary Knits Red Knickers Pretty Badly").

The week ended, not in a climactic banquet, but in a flurry of commonsensical items - how to present vegetables California- style; how to arrange a perfect fruit salad. It was a relief. We stumbled away from the backstreets of Kensington awash with information, quantities, methods, timings, techniques, a whole battery of new ways of handling food. I wouldn't say it turned me into a gastronomic genius in five days. What it did was de-mystify the process of cooking. It told you that making dough and shortcrust pastry and gorgeous puddings are within your capability; that your life need not be an unending procession of pork chops and Waitrose yoghurt. It taught you to taste everything, touch it, poke it, sample it, re-season it and not be afraid of it. And it gave you a virtual fetish about copper pans and conical sieves and Sabatier knives.

Cooking the perfect dinner for eight (smoked trout pate, sesame beef salad, profiteroles) may still be some weeks off, but now I know it's a genuine possibility. For the moment, there's pleasure to be had in doing rather small things well. So that, when your guests ask, "What's this orange-y stuff under the pudding, John? Tropicana orange juice?' you can reply, "Oh, just a simple mango and passionfruit coulis...".

Leith's School of Food and Wine Ltd, 21 St Alban's Grove, London W8 5BP (0171-229 0177).