Signature
Mandarin Oriental Hotel, Tokyo
Tel: (00 81 3 3270 8800)
Price: Meal for two, including wine and service, £200 and upwards

In Tokyo they talk about the bubble - the period in the late Eighties when asset prices went through the roof - as others talk of wars won. It was an aberration, they say, something to be lived through and examined, but not yearned for. Eating at Signature, the French restaurant on the 37th floor of the Mandarin Oriental Hotel in the Japanese capital, it is easy to imagine that these are still hot bubble days. Up here they boast an eight-course truffle menu at £100 a head before booze, and a wine list with prices topping out at a million yen (or £4,500 of your money). Many ingredients will have flown as far as you have to be here, only to be prepared in the style of the land they left behind. It is true eating at altitude, up here above the hard-jewel neon of the night city.

And it is, for the most part, fabulous, in a dislocated, international oh-my-gosh sort of way. To the relief of this newspaper's accounts department, I should declare that I ate there as a guest of the hotel. This should not therefore be considered a review; it's more a dispatch from the front line of wealth, a snapshot of how the moneyed Japanese like to get their jollies. For, while there were a few other foreigners eating at Signature the night I went, the restaurant was not created as a bolt hole for those unadventurous travellers, stupidly queasy at the thought of more raw fish. It was created for the locals, for a nation with a unique enthusiasm for paying top foodie dollar, which right now is happily supporting a booming economy for chefs from other places.

The French chef here, Olivier Rodriguez, originally came to Tokyo to work at the Japanese outpost of Enoteca Pinchiorri, the Michelin three-star restaurant in Florence. Two years ago, like some culinary Beckham lured into the equivalent of the LA Galaxy, he was set up at the Mandarin Oriental with a brief to create a restaurant that could take on the competition, which is very serious indeed: Pierre Gagnaire has a restaurant in Tokyo, as do Gordon Ramsay and Alain Ducasse, Alain Passard and Joel Robuchon (thrice over), Paul Bocuse, and Michel Troisgros. The Mandarin's designers erected fragile-looking lattice-work screens to separate one part of the hotel lounge from another, and trusted that the staggering views would do the rest.

And then Rodriguez went to work with the truffles, as was expected of him. The Japanese have a pronounced taste for delicacies - chinmi, as they refer to them - which extends unto the holy western trinity of truffles, foie gras and caviar. Almost everything I was served involved truffles in one way or another, including the ice cream. And, curiously, most of it worked in spite of, rather than because of them. Admirably, the kitchen here avoids punching up the taste with truffle oil, but this late in the season the nubbly black diamonds were either not at their best or, like me, knackered from jet lag. As a result, the dishes couldn't rely on this for their effect, like fat men relying on good tailoring. They had to depend on cooking alone, and for the most part they succeeded.

A dish of both cooked and raw asparagus, the latter sliced thinly and curled over like a plump ocean wave, was a crisp, brisk salad, butched up with shards of Iberico ham. Seared foie gras, crusted with cinnamon, came with a finely acidulated beetroot puree to cut through the richness. Two beautiful langoustine (wearing overcoats of truffle puree which must have been a bugger to get on) were partnered with a heap of cabbage and bacon and, on the side, a meaty bacon sabayon. There was a smooth pumpkin soup with lightly candied chestnuts, and then, in a moment of luxury overload, a fillet of turbot with both truffles and foie gras. I suppose I should chunter on here about the obscenity of excess, but as it tasted very nice I really can't.

So far so French international. But then came a dish of fresh crab with crisp marinated fennel and aromatic local herbs and a coulis made from sea urchin. And all of a sudden I was eating something which, despite the denatured environment, was in every way - seafood, pickle, herb, the sexy pungency of the sea urchins - Japanese in profile. It seems that, after a few years in Tokyo, even a diehard French chef like Rodriguez could not resist the lure of those Japanese flavours.

There were other things: a tiny pigeon breast with bitter chocolate and almonds, a light mango soup with lychee jelly and lime sorbet, the untruffled truffle ice cream. Being label queens, they poured me glasses of Montrachet and Cloudy Bay, and the waiters did the very Japanese thing of bowing a lot. And at the end I looked out over the city and I decided I had had more than enough and I was ready to come down now.

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