Bennett Oyster, Bar & Brasserie, 4-9 Battersea Square, London SW11

The uncertainty that characterises everything about Bennett's Oyster Bar starts with a telephone call. I rang to book a table and said, "I grew up in Battersea and I've never heard of Battersea Square. Where exactly is it?". "It's off Northcote Road," said the voice. Just to check, I looked it up on urbanspoon.com, the food lover's website, where it seemed to be located somewhere off Lavender Hill. A second phone call to the restaurant established that it's half a mile from either road, in the little riverside enclave off Vicarage Crescent.

Very jolly it looks too, in this charmingly reclaimed bit of wharfland. It was once owned by a coal merchant called Simon Bennett, who ferried the black stuff up the Thames and dumped it in the cellar, prior to distributing it to the hearths of rich folk across the river in Chelsea. The cellar had a second incarnation in the 1970s as Bennett's nightclub, and was apparently frequented by Princess Margaret and Roddy Llewellyn in the heady springtime of their love.

Now it commands the square, full of light and warmth. Inside there are two quite distinct interiors. In the main brasserie, a long table runs down the middle; you can sit on bar stools for informal snacking. We were parked to one side, in an old-fashioned dining room with wooden floor, avocado banquettes, and mirrors that lean forward from the walls to reflect the heads of diners. It's cosy, but just a teensy bit Penge High Street.

The menu confirms that this is an oyster bar and brasserie. Along with the oysters, it offers a dozen seafood dishes and a further dozen standard-issue meat'n'fish dishes suggestive of an upmarket gastropub. This seems to be asking a lot of the kitchen. Bennett's also has a breakfast menu, and bakes cakes for its teatime clientele. But hang on, it also has a special Store, selling wine (which you can drink at your table for a small corkage fee), fruit and veg, and flowers.

I'm surprised they haven't thrown in a multiplex cinema, a bouncy castle and a boutique, as well. The all-things-to-all-men-women-and-children restaurant is a concept that's been struggling into public consciousness for years; it seems to me to require boundless energy and very patient staff. Can there be enough passing trade in this backwater of London SW11 to justify opening for breakfast and tea as well as lunch and dinner?

The Uncertainty Principle extends to the food. Unsure of whether to leave classic ingredients alone or add something to them, Bennett's unerringly goes for the latter option. Angie's margarita was sweet because some gum sugar had found its way into the tequila. Her mixed artichoke salad (three kinds of artichoke, one of which resembled a witchetty grub) with lamb's lettuce had its fresh salad-ness drenched in balsamic vinegar. My razor clams were accessorised with butter beans, red onions – and trace elements of wild boar. The umami taste of the boar overpowered everything else. "It's very unusual isn't it?" said Julia, our lovely waitress. "The chef is going for something... earthy." A shame, I reflected, that he couldn't settle for just fishy. Or, indeed, clammy.

Half a dozen native oysters from Loch Ryan in Scotland were sharply and brinily delicious which, at £3.20 each, they damn well should have been.

The menu promised monkfish tail wrapped in air-dried ham with spinach and gremolata, plus a crayfish risotto. They'd got the emphasis wrong. This was a plate of perfectly acceptable crayfish risotto, with an apologetically shrunk, ham-wrapped monkfish like an afterthought. The ham was lovely, but the monkfish – the most solid and meaty of white fish – decidedly mushy. Bennett's fish pie was 50/50 fish and potato, which I guess is about right for fish pie, and tasted fine – "Although," said Angie, "it's what I'd expect to find in a pub in Sussex". We asked what was in it. "Haddock, pollock, prawns, salmon and smoked salmon," they promised. Angie, already regretting there were no mussels or scallops to be found, could find no trace of prawn anywhere. The waitress disappeared and returned with an apologetic look on her face. "Prawn paste," she said shortly.

Some time around the pear tarte tatin with elderflower cream (the pastry undercooked, the pear in slices rather than chunks), the exceptionally charming and friendly owner, Ray Duhany, told us about his plans. He wanted, he said, to take his cue from posh, old-fashioned English cuisine – with an admixture of La Coupole. A veteran of Scotts of Mayfair and the Atlantic Bar & Grill, he's a chap of tremendous energy and drive, who deserves to succeed. I wish Mr Duhany every success, with the breakfast menu, the teatime, the shop, the wine and everything else. But until the kitchen clarifies its USP, refines its menu and stops adding otiose flavours to simple dishes, it'll be an uphill struggle.

Bennett Oyster, Bar & Brasserie, 4-9 Battersea Square, London SW11 3RA (020-7223 5545)

Food
Ambience
Service

About £130 for two, with wine

Tipping policy: "Service charge is 12.5 per cent discretionary, of which 100 per cent goes to the staff; all tips go to the staff"

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