Shopped: The Shocking Power of British Supermarkets. Joanna Blythman

bones is because they like to buy ‘‘block’’ fish, that’s cheaper fish that have been filleted at speed. It’s hard to see why supermarkets buy fish from all over the world to sell fresh when they can’t even sell fish from the UK fresh,’ he remarked.

      One young, enthusiastic Surrey fishmonger, Rex Goldsmith, gave me an insight into the difference between fish from the independent fish trade and that from supermarkets. ‘I drum into my assistant, ‘‘If you wouldn’t buy it – don’t sell it.’’ I always go for quality,’ he told me. On a sunny spring day, the selection on his slab was as vibrantly fresh as the weather: Whitstable oysters, Cornish cod, brill, skate, sole, Scottish mussels, south-coast line-caught sea bass and west coast scallops. None of it had been frozen. It was the sort of selection that gives you ideas and inspires you to cook.