The name suggests conviviality – yet while its welcome is friendly enough, Il Convivio has an ever-quiet air, as though customers have sunk into silent contemplation of the Dante quotations that adorn the walls. The three distinct dining areas of the restaurant are elegant, airy and enticingly lit, but a certain shabbiness has taken hold, and the puzzling contrasts between promise and presence continue with the food on the plate. Soup brought an instant challenge: while the creamy carrot base complemented by spicy, crunchy sage fritters showed beautifully judged flavours, it proved impossible to cut the giant fritters with the spoon provided. A similar experience came with the trail of resilient greens in an otherwise perfectly executed risotto. Brined duck breast was sublimely tender and flavourful, but its tough skin proved an irritation. White espresso gelato was a joy, petits fours a disappointing irrelevance. Such discordant notes could prove a deal-breaker on the Belgravia-priced carte, but the chef’s set menu seems such a bargain that slip-ups might be forgiven. Wines are well chosen and affordably priced, with good by-the-glass options. Certainly a place worth knowing.