The visceral thrill of a not-so-brief encounter is made more piquant by Bill Borrows’ refusal to dine down market.

Despite the fact that Queen Elizabeth II was born just up the road at number 17, The Square does not suggest any degree of elitist indifference. Oh no. The Square style is ‘correct’, and that is an entirely different concept. Neither formal nor fusty, but correct. The welcome is precise, non-deferential and to this writer’s taste. An aperitif awaits (Chartogne-Taillet Cuvée Sainte-Anne, NV): slightly citrusy, refreshing and drier than Bill Hicks in a sirocco.

The decor is showily un-showy. The tables are spaced far apart on parquet flooring, the walls taupe but for the dynamic and dramatic splashes of colour provided by the work of Deborah Lanyon and, a table of voluble Germans aside, there is not so much a hubbub as a respectful diligence. Even the children present (it is a Saturday lunchtime) behave impeccably.

At every table resides the satisfied contentment of people who have been here before and know what to expect. I also know what to expect and, consequently, thought it might be a perfect place to bring my companion, a married woman with an insanely jealous husband who would take a chainsaw to the neck of an orphaned puppy should it so much as lick the back of her hand.

At the far corner table (I thought it best) we are presented with the signature dish: saute of Scottish langoustine tails with parmesan gnocchi and an emulsion of potato and truffle. They call it an emulsion, I prefer to call it a paraph to offset the rickle of the langoustine, but then most pretentious wankers, such as I, would. It certainly kept Mrs X quiet for almost five minutes.

Chef-patron Phil Howard has a certain roguish way with a langoustine and this feels as utterly indulgent as the addition of truffle might suggest. The service is, once again, ‘correct’. The space allows for a fluidity of movement and elegance of execution. That is to say, dishes arrive at precisely the right time with a minimum of fuss.

I have the salad of cooked and raw spring vegetables with Montgomery cheddar ‘fondue’, crisp quail egg, shoots and flowers to start while Mrs X takes an immediate fancy to the glazed chicken wings with Roscoff onions, Dorset snails, wild garlic béarnaise, nettles and red wine. ‘Quite the best food I’ve had for months,’ she confesses with unusual enthusiasm. It might be the best anything she’s had for months.

The wines are selected are a gregarious Erse Bianco from Sicily before an accommodating Grüner Veltliner. And although I’m not usually a fan of wines produced by the countries involved in the Anschluss, this is a perfect choice. Finally, a lively 2010 Chassagne-Montrachet that didn’t so much hold hands with the slow-cooked fillet of turbot with crushed Jersey Royals, pickled celery, mussels and cider as promise to cherish, love and obey.

Watching Mrs X place a forkful of roast veal sweetbread with white asparagus, cauliflower cheese, hand-cut macaroni and morels between her lips, it is immediately apparent why Mr X maintains such an overarching, if ultimately unsuccessful, surveillance detail. Mrs X wants elderflower ice cream with Granny Smith apples, vanilla and malt crumble and Mrs X tends to get what Mrs X wants. Well, she does if she’s with me. ‘Sumptuous,’ she says.

The cheese is as marvellous as ever. From the strength of the Beaufort (like an unholy gruyère), to the Flower Marie (a soft sheep’s cheese with a mushroomy/citrus taste, if that makes sense) through the Eve and Epoisses and eventually to the Baltic (a Northern cheese with a tang of beer). We ponder where to go next over exquisite petits fours and a glass of Speyside Glenlivet mineral water. ‘Perfectly still’, it explains on the side of the bottle. Again, all very correct. Unlike my intentions. Was that the revving of a two-stroke engine outside? Cheque, please…

The Square, 10 Bruton Street, London W1J 6PU. Visit www.squarerestaurant.com or call +44 20 7495 7100 to book.