There are hot and cold starters, too, including half a dozen oysters on ice, mussels steamed in garlic and wine, and a smoked fish platter. As the kitchen runs out, the items are scrubbed off the board in time honoured fashion.

Look at this wine list. There is a Chablis Premier Cru Dom Gerard Tremblay 2000, just the sort of quality bottle required if you fancy a bit of Chablis, and priced at only £23.50. Order some bread for £3.75 and you get a wooden platter loaded with half a crusty bloomer, hot from the oven, speared with a bread knife and served with a trio of anchovy, red pepper and garlic-flavoured butters.

And the place is packed, with the unmistakable chatter and buzzy hum of happy diners tucking in to a good lunch. We could be on a quayside in France. Perhaps the Italian coast. Or south of the border, down some Spanish way. But we're not. We're slap bang in the middle of central London, just five minutes from Oxford Circus, in a restaurant that time forgot.

Back to Basics is situated in a pretty corner site among the mansion blocks and offices of the area that no one but local estate agents calls Tichfield Village. It's the kind of quiet backwater you can unexpectedly come across in the West End, a place where motorcycle messengers park to sunbathe and eat Cornish pasties while they read their copy of Loot. The clamour and dash that swirls around the Middlesex Hospital is out of sight a few streets away.

Back to Basics has windows down two sides - it was probably once a corner shop - and tables crammed so closed together that only the snake hipped waitresses can weave between them with ease. The tables are of polished wood, the napkins are white cotton, there is a clunky swirl of sea blue mosaic around the bar area and the spherical glass light shades look like different coloured balloons. Some kind of disco music plays faintly in the background. It is London retro, but it's modern manner that is fast becoming a cliché.

What is instantly - startlingly - obvious is that, over the years, no interior designer has tried to twink Back to Basics and give it an urban gloss, no PR company has encouraged it to change the name and throw a cocktail party for Denise van Outen, there has been no attempt to lure a cool crowd across the threshold or impress with attitude. Despite the bustle, it is informal and so unassuming that you can even smoke, although few do. Well, well, well. I can't remember the last time I was in such an unpretentious restaurant.

From the daily changing menu, we start with home-cured gravadlax; a carpet of fine salmon with a dilly, mustardy edge, nicely scattered with razor thin slices of red onion and capers, giving an astringent lift to the fish. The Fisherman's Fish Soup would make a good, quick lunch on it's own; a large bowl filled with a generous amount of fish and shellfish - and not the usual cheap padding, either. There are plump mussels, some lovely clams and assorted bits and bobs of white fish. The stock is good, but perhaps slightly lacking in depth. Who can resist Premier Cru oysters from Scotland at £7.25 for half a dozen? The name is a new one on me, but the rocks themselves are plump and gleaming, excellent with the Chablis.

Main courses are served in generous portions in large, white, shallow bowls. At the next table, two diners are having a wild sea bass and I goggle at the generosity of the portions that arrive; three whole fillets each, all six of them looking golden and delicious on top of their Asian garnish. The standard London restaurant sea bass portion - and not a wild specimen, if they can possibly get away with it - is half of one fillet for about £26, if your lucky. Back to Basics charge £15.50 for it's version; it should be awarded for a gold medal for kind services to long-suffering lunchers.

Meanwhile, back at our table, a stunning fillet of fried gilt-head bream with a crunchy undergrowth of crisp green beans is quite fantastic, as is a big roasted tail of monkfish curved on nubbles of spiced prawn. This seems to be something of a signature dish - oops, dangerous trendy term - but it is easy to see why. Customers are warned that the couscous will be cold and, although it seems odd, it works perfectly.

The kitchen also know when to leave well alone and the comforting simplicity of a slab of excellent smoked haddock sits proudly unadorned and sandwiched between a spinach salad and a softly poached egg, with a yolk that pools down the fish when pierced.

Puddings are mixed - home-made Grand Marnier crepes with oranges good; soggy bread and butter pudding with a brown sugar topping bad. But I am not complaining. At all. Sending out a demanding barrage of perfectly timed fish lunchers and dinners takes an enormous amount of real skill; the chef / proprietor, Stefan Pflaumer, and his team may not have their own television series or marketing gimmick or silly haircuts, but they are very talented indeed.

Finally, how nice to find a friendly somewhere that does not concentrate on charging customers as much as possible for as little as possible and is actually good value and fun. While the food is not haute cuisine, it is good and nourishing and cooked to order by proper chefs. Weekday lunchtimes are always busy, but there are spaces in warmer weather, the restaurant expands dramatically, with 50 seats outside. I couldn't have liked it more.