Bonito con Tomate del Cantábrico

Basque and Cantabrian bonito con tomate is summer coastal cooking: thick pieces of bonito del norte, the albacore of the Cantabrian Sea, held in a concentrated tomato sauce built on onion and green pepper. It isn't marmitako with the potatoes forgotten. Marmitako is a brothy fisherman's stew; this is bonito in a red, glossy salsa de tomate, thick enough to cling to every piece.

The sauce must be completely cooked before the fish goes near it. I take the onion and pepper low and slow until they're dark gold and sweet, the sofrito, or slow vegetable base, that carries the dish. Then the tomatoes cook until their water is gone and a spoon drawn through the pan leaves a path. Only then does the bonito go in. Sear it briefly, settle it into the bubbling sauce, turn off the heat, and cover the pan. The stored heat finishes the centre gently. Give it another five minutes on the flame and tender bonito turns to cotton.

Fresh bonito del norte is the prize, but good frozen albacore, thawed overnight, is the closest substitute. Yellowfin tuna also works; it is darker and firmer, so the short finish matters even more. No hace falta haber pisado España, you don't need to have set foot in Spain. My Margin beside this recipe says only, "sauce first, fish last." Siempre sale, si lo sigues: it turns out if you follow it.