Standing behind the oyster bar of Bentley's, Richard Corrigan, chef-proprietor of Michelin-starred The Lindsay House, was wearing the smile of a man who has come into his rightful inheritance. He beamed. Twelve years ago Corrigan was hired as chef of this long-standing fish restaurant when it was owned by Boddington's of Manchester.

At the time, Jonathan Meades in his Times column described the move as a risk. "It's not that there's anything particularly outré about Corrigan's cooking - the problem is that this chef is simply too good. You do not patronise old-fashioned restaurants to suffer cooking of such quality."

A total transformation of the site, which Meades compared to a fairly grim provincial hotel, has installed surroundings that match expectations of the cooking now that Corrigan is co-owner.

A sensitivity towards the singular Arts and Crafts façade of the Swallow Street building has resulted in agreeably stolid, comfortable first-floor dining rooms with dove-grey panelling and William Morris fabric, and a beauteous ground-floor oyster bar with counter top and tables of pristine white marble, offset by red leather seating and dark panelling.

On different days I ate in the bar and the restaurant, which is referred to as The Grill, and so pleasing was it to see a British stalwart reinvented. Those tourists who have Bentley's, Rule's, Simpson's, Scott's etc on their to-do list - as if nothing has changed in British catering in the past 50 years - should, in this instance, not be disappointed.

In the oyster bar, where London's most charming, idiosyncratic host, Jon Spiteri, manages the floor, we tried simple dishes where the integrity of the ingredients said it all.

Smoked wild Irish salmon from Frank Hederman's Belvelly Smoke House in Cork is a revelation; so much indifferent fish finds its way these days into the market and supermarket. The chickpeas that were a part of an olive-oily langoustine dish seemed particularly young and perky.

Plain grilled Dover sole beautifully trimmed - a fish on a dish - was perfection, and a back of wild sea bass rolled around herbs and fennel was also excellent and handsomely matched with a side order of garlicky spinach. Why the dish of mangetout though, that miserable vegetable which should be phased out?

Nutty soda bread, Crozier Blue cheese soaked in Banyuls - much as you soak Stilton in Port - and a fresh pear frangipane tart sitting on the bar ready to be sliced were other alluring details. One more is the opportunity to have a savoury of Guinness rarebit.

Upstairs, some meat dishes feature on the menu. Bone-marrow-and-rump burger served on a slice of brioche used the marrow to make the meat supple, but unannounced snails in a garlic sauce on top didn't please the recipient, who happens not to like snails. I thought it was a great combo.

Steamed Elwy Valley lamb pudding was a hotpot in a suet crust. Beef does it better. Mixed grill delivered suckling-pig sausage, fillet of beef, belly of pork and lamb chop - a trencherman's dinner. Best of the desserts we tried was Cox apple pudding with Calvados custard.

New improved Bentley's also offers cheerful young waiting staff and a tempting wine list compiled with the help of the notably fine supplier Caves de Pyrène. Corrigan's spirit (and sometimes his voice) spreads around the place. As he has said: "I love our business. I love meeting people. I love the word hospitality.

Hospitality costs nothing. That's what everybody forgets in business - and that goes for all businesses."