J Sheekey is fresh again, thanks to the people behind London's favourite restaurants. Photograph by Dominick Tyler
It may have been the effect of the party I'd just come from, but as soon as I'd been let into J Sheekey by the gallant at the door, I found myself spinning round in a maelstrom of activity, ricocheting off waiters charging past the reception until, before I was aware of it, a man was divesting me of my coat and might have done so without my noticing at all had a cardigan button not snagged on a loose thread from the lining.

Dinner can be a downer after a few drinks, the spirits flagging in the delay between courses, but under new management, this fish restaurant, known for nostalgic fuelling either side of the theatre, kept up such a high-octane performance that it reduced our buoyancy only by making us over-eat. It used to be a tired old warhorse that had been dropped by discriminating guide-books, but in the three weeks since it reopened after a rescue-mission by Jeremy King and Chris Corbin of Le Caprice and The Ivy, Sheekey's seemed to have become the centre of the social whirl. Look, there's George Melly, and Sir Terence Conran, and that actor who played a doctor in something.

As everyone knows, the Ivy is everyone's favourite restaurant, and impossible to get into. At Sheekey's, you don't yet have to pretend you're lunching an It girl to book a table, but you have to do it a few days ahead, and even then risk being sent to eat at the bar. Worse things could happen, as this room has a barber-shop-mirrored beauty of its own. But it doesn't afford the rubbernecking opportunities of the wood-panelled dining compartments linked by the corridor where I was first buffeted by the to-ing and fro- ing staff.

A brilliant restoration has pointed up the best features of the restaurant from every decade this century - abstract etched-glass windows, rows of framed black-and-white photographs of thesps and paintings in styles as wide-ranging as de Chirico and Mark Gertler. "A bit of Lalique glass wouldn't be out of place," said my consort.

A vast shell on a shelf was lit to look like an abstract porcelain sculpture, not the kind of corny marine reference seafood restaurants are usually unable to resist. It's the only clue to the menu's persuasion. That and the crabs and other crustaceans on ice by the window.

Almost wilfully, there are no mussels on the menu. In one of the most surprising restaurants-gobbling-each-other-up moves of the year, The Ivy and Le Caprice were bought by the Belgo Group, which had previously swallowed up the posh trio of restaurants, Daphne's, the Collection and Pasha, and has behind it the youthful tycoon who expanded Pizza Express like a glutton's waistline. Regardless, though, of its ownership, Sheekey's is in the same league as the Ivy.

We assumed they knew how to open an oyster and so shunned fruits de mer for starters. Instead, making them work harder, their brandade took some beating. The creamed salt cod pulled no punches with the garlic, which plus plenty of parsley, was a match for the salt, and had a couple of slender slices of garlicky toast over it; baby squid with polenta that looked like scrambled egg was similarly garlicky and parsleyed, and agreeable, though squid and polenta may not be made for each other; each could to with partnering something with a bit more bite.

This is not the place for lingering over your meal; though Sheekey's doesn't make you feel rushed, the dizzy-making pace and distracting exuberance of a restaurant firing on all cylinders doesn't allow it. We'd almost eaten our starters before our wine (and the glass of champagne the breathlessly bubbly atmosphere makes it hard to resist) and the bread we asked for (and for which we were charged pounds 1.50 each) arrived.

Moments later, before any chance of an energy dip, our main courses were upon us. Smoked fillet of cod with poached egg and colcannon was a perfect rendition of a deliciously undemanding dish; indeed, nothing on the comforting menu requires gossip-inhibiting chewing. The trendiest main course was the peppered bluefin tuna with Italian barley and herb salsa. We could have had grilled or poached fish of the day, or headed towards the pounds 20 mark with seabass, seaweed risotto or Dover sole. The haddock in batter with chips comes in at pounds 13.50. Sheekey's is not a cheapie, but it's tremendously classy for fish and chips.

My lemon sole Belle Meuniere was a perfect white cushion of fish with soft roes and brown shrimps, three ingredients that have been all but musselled out of the way by flashy pan-fried interlopers such as tuna and swordfish. Of the half-a-dozen simple veg sold on the side we had chips and seaweed, and would probably have preferred pommes allumettes if we'd been sharp enough to realise they were an alternative to the chips, which, incidentally, came unintentionally garnished with whiskers, not from the chef's beard, but from a prawn. It's the first time I haven't much minded finding hairs in my food. Seaweed will not be my green vegetable of choice next time.

With a gingery treacle tart and a tremendously serious trifle of thickly layered cream, proper custard, peaches, pears, sponge and raspberry jam, we spent pounds 40 each by the time we'd added on service. The food is good enough, though dishes could do with a bit more definition to make them exceptional. But whether you combine it with the theatre or not, the place and the pace is the thing. With its new cast, Sheekey's will run and run

J Sheekey, 28-32 St Martin's Court, London WC2 (0171-240 2565). Lunch and dinner daily until midnight. Saturday and Sunday lunch pounds 15.50 three courses. Around pounds 25 without drinks. Wheelchair access to restaurant, not toilets. All credit cards.