If you have ever wondered about the fish content of a Birds Eye Omega 3 fish finger or a McDonald’s Filet-o-Fish, the answer is pollack. A minor member of the cod family, its chief virtues are its abundance and its cheapness. Frozen and flown in from the Pacific, it retails at £4.99 a kilogram at Sainsbury’s supermarkets, compared with £15.85 for Icelandic cod.

Yet line-caught English pollack is greatly in favour with some of London’s starriest (in the Michelin sense) chefs. Anthony Demetre, who first put it on his menu a few years back, has pollack dishes at both his restaurants, Wild Honey in Mayfair and Arbutus in Soho, where – dressed with sweet peppers and fennel – it is one of the most popular dishes. Angela Hartnett will be offering braised pollack with preserved lemons and courgettes at the York & Albany in Camden Town when it opens in late summer. Tom Aikens sells it deep-fried in beef dripping at Tom’s Place in Chelsea. And Gordon Ramsay has it on the menu at Plane Food, his outlet at Heathrow’s Terminal Five, fried with bacon in a red wine sauce for £15, the price he charges for Loch Duart salmon.