This week I have decided to begin with the bottom line, and here it is: £97.31. Expensive, no? OK. How about this. We managed to spend that £97.31 at Deca without a single alcoholic drink. As I put my credit card back into my wallet I thought it might burst into flames, it was so damn hot. The man to blame for this extraordinary feat is Nico Ladenis, who remains the only self-taught chef in the world to have been awarded three Michelin stars, at Chez Nico on Park Lane.

Back in 1999, he announced he was returning those stars to Michelin. This was, of course, patent cobblers. No chef can 'give back' their Michelin stars; they are awarded anew every year. All Ladenis could do was ask Michelin to stop inspecting him. There were mutterings that really the restaurant was finding it hard to sustain three-star status and that he therefore preferred to pull out altogether. Whatever the reason, Ladenis, who had health problems, retreated from the stove to his house in Provence. Now Chez Nico has been closed down and he has opened this new place just off London's Regent Street, though here he is patron rather than chef. I am told it is meant to be a brasserie much like his other London restaurant, Incognico. By which he must mean a brasserie for very very rich people.

Part of the outrageous cost has something to do with the look of the place, I think. It has been designed by David Collins, the must-have interiors man of the moment. As so often with Collins, it is an amber jewel box of a room with subtle recessed lighting and deep chocolate banquettes and, with every spoonful of food, you know you are settling his final invoice. The food itself is mostly fine if a little odd, though fine and odd are not words you would normally associate with a bill of £97.31.

Our canapés, for example, were delicate oblongs of quiche. They were OK oblongs of quiche, but they were still quiche. It seemed such a sweet retro 70s touch that I decided to stick with the theme for my starter by ordering the dressed jumbo prawns 'cocktail'. I assumed those inverted commas to indicate a certain irony. Not a bit of it. This was a prawn cocktail down to the pink Marie Rose sauce. It was not a great argument for the dish and definitely not at £12.50. My companion, Sarah, did better with a tian of dressed crab, the top layer of which was a robust disc of the brown meat dusted with cayenne. The accompanying celery rémoulade was, however, distinctly underwhelming.

Thinking I could now leave the 70s theme behind, I ordered breaded sweetbreads 'Pojarski', not having a clue what the last word meant. I now know it refers to a 17th-century Russian prince who defeated an invasion by the Poles. Here it also referred to a crisp-fried disc, within which the sweetbreads were bound together with shreds of pork that overwhelmed them.

This may sound unnecessarily cruel, but it really did remind me of something Findus might have invited you to throw in the deep-fat fryer. Sarah's chargrilled fillets of John Dory had been cooked sensitively and dribbled with olive oil. She was clearly ordering better than I. With these we were informed that we would need side orders - green beans and spinach at £3.50 each - bringing the cost of mains to over £20.

I finished with a refreshing cocktail of orange segments in a light caramel sauce, that came in one of those glasses you used to see on the front cover of Good Housekeeping cook books, and Sarah struck lucky again with a rich pear tart. By comparison, the £6.50 charge for each of these seemed almost reasonable. Almost but not quite. And then came that bill, including a tenner for service which is on the joyless side of formal. Now I know restaurants in London are expensive. I know rents are high and that David Collins has his mortgage to pay. But does that really excuse these prices? Incidentally, the dining room was only half-full. I wonder why.