Yes, it's Salmon yet again

The site, formerly Coast, is in a street positively throbbing with glamorous, expensive restaurants, adequately servicing the moneyed neighbourhood; there are a number of high-end Japanese outlets within staggering distance (admittedly not with the evolved kind of menu offered by Sumosan), so it is hard to think of a compelling reason to visit. It is also curiously featureless, apart from a stunning installation of shimmering, ethereal Venetian glass from metal barnetted designer Che Frantz-Jeffrey, where slithery shards are suspended on invisible wires and shot through with precious metals to give the impression of a shoal of exotic fish. When you examine the beige/stone/taupe fixtures and fittings, you realise that a lot of money has been spent on the place: the tables are thickly lacquered (macassar wood, apparently); you're sitting on buttery suede; chairs are properly substantial, comfortable pieces of furniture; still, the impression is of a hotel restaurant in an international, corporate chain full of dull, expensively-dressed business people.

Turns out it is an international chain, one of a handful owned by the London - resident Wolkow family; when in Moscow, we're told that Naomi Campbell won't eat anywhere else (like that's an inducement to call in...). And you'd need to be on her kind of money because prices are up there with Nahm, Mju and, of course, Nobu. After looking at the figures, we went for the special tasting menu - £55 a head before you touch so much as a sherry - on the premise that, due to chefly grandstanding, you usually get a lot more for your money. It is also, for the same reasons, a great way to see what the kitchen's capable of. Normally, one of the thrills of doing this is an opportunity to experiment with stuff you wouldn't usually order. Sadly, our selection of six different dishes each trod a mind-numbingly safe path, the food as luxuriously bland as the clientele. Our blamelessly fresh sushi and sashimi was gloriously presented - all woven mooli and sculpted fish flesh - but was limited to tuna, shrimp, salmon, seabass and yellowtail: all perfect for those who approach Japanese food with trepidation.

Salmon appeared four times: as sushi and sashimi; in a seared sashimi with ground onion dressing almost identical to one I ate at Ubon; and as a rather delicious tartare topped with caviar. Tuna also turned up in two tartares: one in a trio with the salmon and one, roughly chopped with under-ripe avocado hiding a poached quail's egg. Lobster put in a double appearance, its claws dressed with what tasted like Marie Rose sauce, nesting in a profusion of the utterly pointless lollo bianco lettuce; and grilled chunks served in the half shell with fish sauce. The only deviation from the relentless procession of the same fish came with three undersized and overcooked lamb chops on a bed of pedestrian stir-fried veg. None of this was downright duff, to be fair, but where was the thrill? Where was the adventure? Where was the eel, or sea urchin, or legendary Kobe beef? It is one of the rare occasions I've had to actually refer to my notes to remember what I ate.

In fact, my overwhelming impression of Sumosan was one of slight, beige-tinted boredom, only relieved by the helpfulness and gorgeousness of our waitress, a ringer for Snow White, and the frisson caused by our £160 plus bill.