La Noisette, London SW1

Are we witnessing the death of the menu? At the new La Noisette, there is à la carte at £45 for three courses, and a charming "summer tasting menu" at £55. But the one the chef really wants you to order is the "inspirational menu" at £65, which doesn't exist. He creates your meal for you on the spot, guided by "this morning's market or today's mood", adapting it to your specific desires and needs.

More than 20 of these non-menu menus are ordered every night, and every one is different. It's a brave, ambitious idea, but I hate it. I don't want surprises when I go out for dinner; I get enough of those when I cook my own meals. Besides, how bored with London or with life would you have to be, to not want to order what is already on the menu here? Witness the almond gazpacho with smoked paprika shrimp and tomato sorbet; wild trout with English peas, beurre rouge and mustard emulsion; and salad of slow-cooked cod, Jabugo ham and squid.

The dashing young chef of La Noisette, Bjorn van der Horst, is obviously one of those "If I rest, I rust" boys. He was head chef of the lovely Picholine and then Gaia in Manhattan, before moving here with the Marc group to reopen the Greenhouse, where he worked his way into one Michelin star and was heading for another. For some inexplicable but probably financial reason, he then linked up with Gordon Ramsay, possibly not the easiest of landlords, in order to set up shop in his ex-Pengelley's Sloane Street gaff.

Thank the lord I didn't go for the inspirational option, or I might have missed out on a genuine star; one of the world's great first courses. But first, there are nibblies of slim pastry sticks with sumac-dusted labne (yoghurt cheese) and picholine olives, followed by a shot glass of warm and satiny artichoke veloute, and a crisp, savoury cone filled with a tongue-tingling, summery hit of tomato fondue, sorbet and espuma (foam).

Then it arrives - a superbly rendered "poule au pot" of tender, succulent pieces of poached chicken sitting in a glistening, loose, intensely chickeny jelly with a hint of acidity for freshness. Set in a neat, lidded French white terrine, it is topped with a round of rich, lush, salt-cured foie gras and finished with celery leaves and baby rock chives, with a pile of still-warm toast wedges on the side. Style, finesse, harmony, and irresistible summeriness in one.

Parisian sommelier Fabrice Hequet has produced a captivating, modern wine list, jazzed up with a good showing from Austria, Germany and Alsace. With the chicken, I am nudged towards an elegant, perfumed, slatey Heymann-Lowenstein 2004 Schieferterassen Riesling from the lower Mosel. When seeking a red for the Welsh lamb shoulder and sweetbreads "à la bouquetiere", Hequet talks me down in price to a £30 bottle of Wandering River Pinot from Hawkes Bay that is intense, bright and fresh - and served correctly at precisely 16C.

It's an easy match with the picture-pretty dish of nuggets of full-flavoured lamb shoulder and gentle, giving sweetbread, strewn with baby vegetables and sauced with a serious but not cloying jus. As always, there is a surprise - an undercurrent of anchovy in the lamb, which lends it a rustic, Provençal accent.

I like the freshness here, in the attitude of the floor staff, and in the thinking of the kitchen. A refreshing watermelon "carpaccio" topped with pinches of light, curdy, goat's milk feta, rocket and a crisp beignet of courgette flower is inspired, elegant simplicity. Meticulously trimmed grilled red mullet fillets with tapenade and tubes of feather-light ricotta gnocchi is all about balance and poise. And although I have to wait an extra 15 minutes for take two of a fromage blanc soufflé, it has a dreamy, subtle flavour and a ravishing toasted almond ice cream.

Van der Horst's style is classical and technique-driven but always modern and delivered with a New Yorker's confidence that justifies the Sloaney prices. A rare let-down is a panzanella salad of bread, heirloom tomatoes and pasta - I have better heirloom tomatoes on the windowsill at home from Tony Booth at the Borough market, and the pasta twists are raw and pasty at the knots. I also thought the signature dish of caramelised foie gras with coffee and amaretto foam was over-cooked, reducing too quickly to grease.

Nevertheless, van der Horst ranks in the top handful of chefs cooking in London at the moment. The room is now clubby, corporate and hazelnut-brown; although it does feel as if it could easily be reinvented as a chief executive's boardroom by next Monday if need be.

At this rate, I doubt if need will be. Just two weeks in, it was difficult enough to snare one of the large, well-spaced tables, although Michael Caine and David Frost seemed to manage it without too much trouble. Booking times are also ruthlessly staggered, no doubt to protect the kitchen from the possibility of 65 simultaneous orders for the inspirational menu. Make that 64, actually, as I find the experience inspirational enough as it is.

La Noisette, 164 Sloane Street, London SW1, tel: 020 7750 5000. Lunch served Monday to Friday; dinner served Monday to Saturday. Around £170 for two including wine and service

17/20

Scores 1-9 stay home and cook 10-11 needs help 12 OK 13 pleasant enough 14 good 15 very good 16 capable of greatness 17 special, can't wait to go back 18 highly honourable 19 unique and memorable 20 as good as it gets

Second helpings: Other edibly named French restaurants

L'Ortolan Church Lane, Shinfield, Berkshire, tel: 0118 988 8500 The ortolan is a small bird, traditionally roasted on skewers in Landes. You won't find ortolan on Alan Murchison's summer menu but you will find foie gras with pain d'épices and suckling pig with herbed gnocchi.

La Poule Au Pot 231 Ebury Street, London SW1, tel: 020 7730 7763 For more than 30 years, this fiercely Gallic enclave has been serving up a mix of French kitsch, candle-lit romance and bistro cooking, including the poached chicken for which it is named.

Souffle 31 The Green, Bearsted, Maidstone, Kent, tel: 01622 737 065 Set in a 16th-century cottage overlooking the village green, Nick Everden's popular restaurant is not short on charm. Neither is the menu, running from pan-fried scallops to herb-crusted salmon - and soufflé.