Langan’s, a brasserie off Piccadilly with curling orange neon signage calling its name, is under new management after it fell into administration in 2020. It is a famous brasserie — London’s version of La Coupole — once owned by Michael Caine, a famous actor, and Peter Langan, a famous drunk, who would crawl across the floor and bite customers’ ankles and who once put out a kitchen fire with champagne. It opened in 1976 on the site of Le Coq d’Or and was treated by the diary columns as a person in itself, as famous as Annabel’s, Peppermint Park and the Ritz Hotel. Lucian Freud and David Hockney and Princess Margaret came here. Hockney designed the menu, a copy of which is in the National Portrait Gallery, and there are three portraits of Langan in the gallery’s collection, all posed differently, as if he is a drunken Mr Benn: one in front of a picture of Venice; one with tie flying, as if in a wind; one clutching a nude sculpture of a woman. ‘High living’, the gallery notes call Langan. It’s a euphemism for madness, and he died in 1988 at 47 after setting fire to his own house.

This is his other house. And, like La Coupole, which calls itself ‘mythical’ on its website — is the food then mythical too? — Langan’s is still self-involved, existing on the fumes of the past. It still has plates with Langan’s name on; if you seek his memorial, look down. Around these curios is a vast and handsome room on Stratton Street, with mad art, pale walls, marble floors and Murano chandeliers. It is, on a Friday evening, filled with shouting people getting very drunk. I don’t mind people getting very drunk — why would I? — but I believe, at these prices (Hockney’s menu has chocolate mousse for £1.20 and rice pudding for £1, but that was long ago) they deserve a better song than this.

The prices are insane: £87 for a plate of seafood for two; £39 for a dozen oysters; £89 for a roast chicken; £39 for a veal chop. The drunken seem pleased to pay it, and shout happily. But though the room is bustling, it is not well run, which is something you could never say about La Coupole, even if it is mythical. (Of course, mythical restaurants are better. They do not exist.) There are too many diners and not enough staff. Our waiter does his best, but he seems to be caring for — or attempting to — perhaps a third of the tables. Or perhaps two women dressed as tarmac do not deserve the same attention as four men dressed as men. The food, meanwhile, cannot be called anything other than repulsive. It is, I think, in ten years of restaurant reviewing, perhaps the worst food I have had. The spinach soufflé is a damp, green thing, served with an evil yellow sauce precisely the colour of the ‘cheese’ in a McDonald’s burger. The ‘bangers and mash’ is a ghastly curl of over-spiced meat of many kinds on a lick of mashed potato, with a dense and inedible sauce. The Jerusalem artichoke risotto is all wrong: halloumi cheese sits in it, pondering its future. We do not bother with pudding — or rather we buy it at Marks & Spencer next door.

As I leave, I look at the drawing of Peter Langan by David Hockney, which is this restaurant’s Sistine Chapel and almost the only thing to recommend it. (I do not hate the chandeliers or the floristry.) Here, holding an umbrella, he looks almost as unhappy as my guest. His alcoholism became a morbid tourist attraction, and what magic this restaurant holds in its rooms is the thinnest kind — the magic of the dead and unhappy man. If he were here to see what Langan’s is now, he would be unhappier still.