The fashionable, flashy restaurant is dead. I know this to be true because I read it in a newspaper supplement on Sunday. Cool places, apparently, too quickly become tepid and customers are no longer satisfied with the knowledge that a venue has celebrity backers - or even a celebrity clientele. Celebrities are a dead loss, actually. They will go to an opening party to eat and drink for free and then never be seen again.

Another revelation in this shocking story about the decline of glitzy eating in central London is that restaurants lacking celebrity backers have been forced out into recherché postal districts. There the locals, who know a good thing when they eat it, don't bother to get taxis back into town to places where someone on the phone has been snotty when they tried to book. Proof of everything you have just read is enshrined in the newly opened Upstairs Bar and Restaurant in Brixton.

The entrance, a small door in the wall in Branksome Road with just a tiny name-plate by the bell, reminded me of some of the places that have sprung up in New York's Lower East Side (New Yorkers - always ahead of us - are said to be bored with restaurants and are having people round to dinner). My friend Kate said that the anonymity of the premises put her in mind of Berlin.

Anyway, this is the deal. A Frenchman, Philippe Castaing, who owns the Opus Café on the ground floor of the building, has now opened a cosy bar on the first floor, and a small restaurant on the second floor, with two French colleagues. (His chef Daniel Budden was previously working at La Trompette in Chiswick.)

The bar, and then the restaurant as we followed one another up the narrow staircase, was full of the type that used to be called yuppies. There is probably now a new acronym for youngish people who have discovered that Brixton has some very agreeable Georgian terrace houses for which they can afford a mortgage. One group had brought with them a very small child, which I have noticed is the chic new restaurant accessory.

The staff and Castaing himself are efficient and unusually amiable. Upstairs is the opposite of pretentious; it is just of its time. The regularly changing menu has three choices in each of the three courses and an option of well-chosen cheeses as an extra.

The cooking is more modern European than French - or you could just say likeable. A cauliflower velouté was unctuously creamy, mackerel escabeche not marinated quite long enough but garnished with lovely sliced carrots and onions, foie gras ballotine neat and rich and partnered with toasted brioche.

In the main course, bavette (the cut of beef we call skirt) with caramelised shallots was the classic French presentation, the slices of meat rare enough to be tender, with a red wine-based sauce; red mullet and squid in the shape of both rings and tentacles swirled around with an inky sauce with fennel risotto served separately in a little bowl was a fine composition; polenta with mushrooms and smoked raclette an enterprising vegetarian assembly.

A bit of mediaeval England crept in with the dessert of lemon posset (similar to a thick cream) with red berries. Poached pear with chocolate sauce is the
sort of dessert that was favoured by yuppies at dinner parties but they never used chocolate so high in cocoa solids.

The short wine list has been cleverly compiled and in the reds can take you from £12 to £180 in 20 nimble leaps and bounds. Kate, who is in training for the Marathon des Sables (running in the Sahara), searched her memory and pronounced the cocktails original and also cheap, which they are at £5 a go.

Wood-burning fires in both bar and restaurant make Upstairs homely, which is obviously the new glam.