Zinc Bar & Grill Fulham Island, 11 Jerdan Place, London SW6

This is Sir Terence Conran's fifth Zinc Bar & Grill, and my fourth. They loom up out of the gloaming in our provincial cities like saviours of the stomach, promising a decent meal and a touch of urban polish, rather than the unknown quantity – and quality – of the new.

The Zinc open-kitchen-bistro-bar concept has been rolled out to Manchester, Birmingham and Edinburgh from the original London Zincquarters. This is a concept that works best where it's needed most. In W1, it's not a big deal, surrounded as it is by significant restaurants such as Embassy, Sartoria, Sketch and Momo, but Fulham is another matter.

As I skulk past a Slug & Lettuce and a boarded-up Vietnamese café towards the shadowy work-in-progress that is Fulham Island (no water – this is more your land-locked island of opportunity for property developers), the new Zinc Bar & Grill gleams in the darkness with a come-hither glow.

Along its windowed length runs a line-up of out-of-season market umbrellas cooling their heels until summer, while inside the door-manned door is a hot-pink ZINC logo and a good-humoured Thank God It's Friday young crowd doing an extremely good impression of people enjoying themselves.

The split-level space is divided between cocktail bar and restaurant, with each parasitically feeding off the other quite successfully. In a normal climate, this would be a light, bright space but here-and-now it's all darkly loungey, like a Conran Shop with the lights switched off.

The menu is not overly grill-oriented (burger, steaks, tuna), listing a happy mix of bar-snack starters (tapas, prawn wontons), French country dishes (guinea fowl and lentils, Toulouse sausage and cabbage) and British comfort food (fish and chips and lemon sole).

Surprisingly for a Conran establishment, the crustacean contingent is reduced to just moules marinière and crab cakes, suggesting either a bowing to hard times or a dismal view of the wallets of local diners. Those who love nothing better than a few freshly opened oysters followed by a crusty rib-eye and chips – OK, me – have a right to feel miffed.

So moules marinière (£6) it is, and it's a generous serving of firm but not overcooked mussels, the cream sauce enlivened with the grassy bite of wilted parsley leaves. Just that one little move – whole leaves instead of boring-old-finely-chopped – says good things about the intelligence of the kitchen.

Tapas (£6.50) is presented rather oddly, on small square plates, and all require forks rather than fingers. 1) Patatas bravas of fried spicy potatoes with aioli; lush and lovely, 2) sweet strips of red pepper dressed with tiny capers and anchovies; a fabulous dodgem ride for the tastebuds, 3) chorizo sausage and white bean stew; soft, bitsy and blah.

The room soon fills up with people called Julian, Rupert and Alexandra, all of whom look pulled from the pages of the latest Conran magazine. Then again, so do the mirror-backed banquettes, the macro-urban art, the scatter cushions, the bistro water glasses and the dark wooden chairs.

Floor staff are young puppies still flopping over big feet, but they are eager to please, they know the menu and are just plain, old-fashioned nice. They are more upset than I am when a jammy, rich Warwick Estate South African Pinotage (£24.50) comes from its storage space so warm, it is practically mulled.

Main courses are perfectly good without being any more so. A simple marinated poussin (£14) from the grill menu has been spatchcocked into subservience, with a disc of herbed butter sliding over it like an ice-hockey puck. It has a comfy spit-roasted, well-seasoned quality, the juicy meat falling from the bone.

Oddly for a grill, there are no steak knives. There's no rib-eye either, so I go for a 300g New York sirloin (£14), a decent piece of meat with a perfect diamond-pattern from the grill, cooked spot-on medium-rare. Perhaps with the low-cal clientele in mind, it's fairly lean and tastes only of meat, which is never as delicious as when it tastes of fat.

Accompaniments arrive in lovely white bowls (Conran); and a creamily dressed salad and a side order of bright green peas tossed with a chiffonade of wilted lettuce and crisp bacon is so French-tasting it should be wearing a beret. Terrific bread comes on a beautiful bevelled wooden board (Conran) and big, golden chips in a curl of greaseproof paper in a bowl (Conran). It is all very dream home, positive living, aspirational stuff that makes you feel as if you, too, could be on the cover of a Conran catalogue.

Puds aren't worth going on about; an apple strudel (£4) gets lost in its own dry and stodgy deconstruction, and a banana tatin with rum and lime sauce (£4) tastes of not much more than sweet stickiness.

Zinc Fulham Island is doing a good job, with its fair prices, good vibe, and the fact that there is someone in the kitchen who can actually cook. It just needs to stock up on some oysters and marbled steaks, move the wine to somewhere less tropical, and send someone shopping for some steak knives. As luck would have it, there is a very good designer homeware store in Fulham Road, Chelsea currently selling Elite stainless steel steak knives for just £6.95 each.

Tel: 020 7386 2250. 10am-12am, Sun until 10.30pm. About £75 for two with wine and service