High Holborn slipped into this world with very little fuss. No opening party (or, if there was one, I was not invited, no celebrity boffing, no magazine profiles, no hullaballoo. One day it was a building site on a rather undistinguished stretch of the rather undistinguished High Holborn, the next there it was, open and ready for business. This quiet modesty extends to the outside of the restaurant. So well-behaved is it, you could easily miss it. But the modesty stops at the front door.

The inside is a riot of colour and designery statement, with banquette seats in British racing green racked up the walls like inner tubes piled on top of one another, with lights like huge inflamed gonads dangling from the ceiling, and with wall colourings that follow the new fashionable theory of opposing colours, or clash, as we used to call it. If all that sounds unpleasant, it isn't. Baffling, perhaps, but fun.

The stern elegance and impeccable cleanliness of the lavatories is deeply reassuring. The service, too, is very good: bespoke-tailored, smiling, efficient and charming.

Before I arranged to meet Pantagruel there, I had already registered that the chef is David Cavalier, a talented cook whom life has not treated as kindly as it might. Consequently, it is some time since the wider public have been able to enjoy his food. Now we can - and, I must say, it has been worth queuing up for.

I had, in fact, already eaten in High Holborn the week before - the week it opened, in fact - which is not my usual practice. On that occasion, I had a salad of pigs' trotters and new potatoes with sauce gribiche and then smoked fillet of whiting (or "merlan", as the menu insists on calling it) with bubble and squeak, poached egg and hollandaise sauce, followed by a carpaccio of pineapple with coconut sorbet. On that occasion, my companion, Clothilde, made short work of asparagus with a poached egg and a truffle dressing, and then of fillet of lamb with courgettes, asparagus and broad beans, ending with a lemongrass and raspberry crème brlée on the reasonable grounds that crème brlée and raspberries are two of her favourite foods in the whole world.

So, by the time that Pantagruel and I had put to the sword duck rillette, watercress and mustard salad and a fish soup with rouille, grated cheese and crotons; roast mackerel with spiced chickpeas and best end of lamb with aubergine and courgette tian; and peach Melba and the carpaccio of pineapple again - all off a generous and splendid menu du jour - I had a pretty good feel for Cavalier's way with ingredients. First off, the menu descriptions are as brief and to the point as the dishes are elegant and sophisticated. The rillettes were as advertised, but glazed with a splash of light béarnaise and layered between two tiny poppadoms spotted with mustard seeds. Well, blow me, this isn't the hunky, hefty stuff you get from your local traiteur; it's light, delicate, yet knee-tremblingly rich. The salad alongside was a thoughtful mixture of leaves, with a sweetish dressing that insinuated itself to the duck with ingratiating charm.

The pigs' trotter salad that I'd had a few days earlier was a similarly refined treatment of a hefty classic, which lost nothing and gained much in translation. The poached trotter had been boned out, formed into a round sausage held in its own jelly, sliced and laid on top of the potatoes with a rich and pungent sauce splattered around. So you got a bit of mild meat in a mild jelly, the firm and earthy potatoes all lubricated with a sauce that combined unctuousness and acid in equal parts.

Combining a highly characterised, not to say oily, fish with chickpeas spiced with chilli; the deft cooking of the lamb; the adroit seasoning of all dishes; the way in which vegetables were built into the totality of the dishes; the nifty reworking of classic combinations; and, above all, the unfaultable technique, which meant that each element of each dish was made as it should be (the fish soup was an exemplar for others to follow, if they can)... I mean, when was the last time you had a serious peach Melba, or even hollandaise?

This care and consideration reached right through to the puddings. The carpaccio of pineapple was an exceptionally satisfying and clever variation on a well-worn theme, the texture and tartness of the fruit lending itself brilliantly to the treatment (and something you could do at home if you have a slicing machine). None of this is revolutionary stuff. It fits easily within the canon of French cooking. It is French in its technique and tastes. Such intelligence and technical mastery are quite exhilarating in the midst of so many examples of extravagant, ill-assorted experimentation.

Lunch with Pantagruel came to £75.50. The eating bit took up £46 - that is, two set-price lunches at £23 for three courses - and £20 went on an outstanding bottle of Corbières (the wine list is building up a strong contingent of decently priced regional French wines in the hands of the disarming sommelier, Frédéric Brugues). The usual bits and pieces accounted for the rest.

If, as claimed by Anthony Bourdin recently, you can judge a restaurant by its loos, High Holborn should do very well. On balance, though, I think Cavalier's cooking will have a bigger part to play in its success