THE PAN is bubbling like a witch's cauldron. I'm watching the three Michelin-starred chef Heinz Beck cooking “salt cod snow” in liquid nitrogen. But we're not at his restaurant, La Pergola, in Rome, but are halfway through one of two four-hour demos at Castello Banfi wine estate in southern Tuscany.

I don't know any other cookery course that gives you so much time with someone of Beck's stature - so I'm lapping it up. Not that I'm going to try this at home - cooking with liquid nitrogen? But the rest of the dish - amberjack cooked in garlic-flavoured oil on cannellini beans turns out beautifully, and can be done pretty much by anybody.

Beck is Rome's leading chef, and the only one, at present, with three Michelin stars. And the only one, as far as I know, who is a certified sommelier - you get to learn about cooking with wine as well as cooking for it. Beck is not Italian - he is German, cooking in an American hotel, the Cavalieri Hilton (though nobody seems to find this amusing but me).

His food isn't really Italian either. It's a “light cuisine of Mediterranean flavours” (his words) paying homage to local produce, which he transforms in ways that make it impossible to put a national flag on. So what's he doing out of his restaurant? Well, La Pergola is shut from Sunday night, reopening on Tuesday for dinner, so rather incredibly for us, Beck has decided to hang out at Banfi. We meet up with him again, at La Pergola, at the end of the trip for an eye-popping dinner, an optional extra to the three-night package. We watch him carefully removing the skin on the cannellini beans, which he declares are “too indigestible”; then he cooks a handful of cherry tomatoes with extra-virgin olive oil and peperoncino until the tomatoes just collapse, before straining them through what looks like a towel. “Finer than muslin - I want a transparent sauce,” he says.

The amberjack fillets are placed in a plastic bag with olive oil and two cloves of garlic to “cook” for 20 minutes at 50C (122F). He uses a water bath, but suggests that we monitor it at home with a thermometer, topping up with hot water when needed, before removing the garlic at the end of cooking. “I don't use chopped garlic because I don't want guests feeling bloated, and this way you get all the flavour you need,” he says.

The next day we discover the real reason for Beck's presence at Banfi. His old sous chef and mate, Guido Haverkock, is heading up the kitchen here. But Haverkock's cooking is nothing like that of his old boss - it's poshed-up Italian with dishes such as shellfish consommé with grouper tortellini, and duck breast with potato flan and porcini mushrooms.

Staying here is something else. The guest rooms are built inside the stone houses that cosy up to the walls of the castle. The former 18th-century hamlet, abandoned five years ago like so many others, was bought by an Italian-American family, the Marianis, in 1978, and the restoration finished last spring with the hotel. The nearest town is Montalcino, 16km away. It is also the name of a wine, Brunello di Montalcino - the youngest of Italy's prestigious red wines, invented in 1888 - and Banfi produces some of the best. You taste a lot of wine on this trip, but if that isn't enough for your palate, Banfi lays on other gustatory events as part of the Beck visit, including one to an olive-oil mill.

Beck at Banfi package is €2,500pp, based on double occupancy, or €3,100 for single occupancy. Further information on Beck and Banfi: www.castellobanfi.com and www.heinzbeck.com. Michelin's ratings will be announced next Wednesday. For more Michelin-star cookery schools, see timesonline.uk/realfood

Times recommends

• 'New York has lost its edge'
• The UK and Ireland's 25 best Christmas events
• Chalet Chef 2010: the winners