You don't have to be a Chelski wife to go to this new fish restaurant, awash with posh on the borders of Belgravia, but it helps. It's early days, but already the place to be seen is at one of the outdoor tables. Inside is very, very white, where we felt like we were sitting in an art gallery, but then maybe that's because we were surrounded by poseurs, alongside a hilarious mix of collagen-lipped blondes and Eurotrash boys.

The menu is seafood only, which is lovely and healthy, you might think, unless, like me you're dining with someone making a documentary on the eco-disaster of overfishing. "Did you know halibut is now so endangered you might as well be eating a panda?" he tutted. I blame him for the fact that my exotic starter of frozen sea urchin (£11.50) turned up as appetising as a small bowl of panda poo - and it tasted about the same, too.

I'd expected something neat and sushi-like, but it looked like an eating dare on Jackass. Needless to say, I couldn't manage it all. My main course was accompanied with more environmental tut-tutting. "I'd like to know the death rate on that," he said of my perfectly poached sea bream intensified by black olives and caramelised shallots (£17.75). Whatever: it was still divine.

I think he was just jealous: his lobster spaghetti (£16.50) - the most sustainable choice he could find on the menu, apart from the bread basket - gave him a noisy stomach the next day. This is a top place to impress a date, but it's so up itself that I worry it may not be sustainable, much like its ocean-depleting menu. Larushka Ivan Zadeh

10 Lower Belgrave Street, SW1 020 7730 9022 Three-course meal for two with wine and water, £100