Bonito con Tomate del Cantábrico

Ingredients

Equipment Needed

• •Wide heavy sauté pan or low casserole with lid, 28 to 30cm
• •Broad frying pan, about 26cm
• •Food mill with medium disk, or blender and fine sieve
• •Instant-read thermometer

Instructions

1. 1

   Cook the sofrito

   Put 60ml of the olive oil, the onion, green pepper, and 2g of the salt into a wide heavy pan. Cook over medium-low heat for 25 to 30 minutes, stirring every few minutes. The vegetables should soften, lose nearly all their water, and turn dark gold at the edges without browning hard. Add the garlic and cook for 2 minutes more. This slow sweetness is the floor of the sauce; high heat leaves the onion pale and sharp.

   If the vegetables begin catching before they're soft, lower the heat and add 15ml water. Let that water cook away completely before adding the tomatoes.
2. 2

   Reduce the tomatoes

   Add the fresh tomatoes and another 4g salt. Bring them to a gentle simmer, then cook uncovered over medium-low heat for 35 to 45 minutes, stirring more often as the sauce thickens. With canned tomatoes, allow 25 to 30 minutes. The raw smell must disappear, the colour must deepen, and the watery pool around the vegetables must be gone.

   Use fresh tomatoes only when they're ripe enough to enjoy raw. If they're pale and hard, 800g of good canned whole tomatoes gives a rounder, less summery sauce, but a better one.
3. 3

   Pass the sauce

   Pass the mixture through a food mill fitted with its medium disk, pressing out the pulp and leaving the skins and seeds behind. If you don't have a food mill, blend it and push it through a fine sieve. Return the sauce to the pan and simmer for 5 to 10 minutes, until a spoon drawn across the bottom leaves a path that closes slowly. Taste and correct the salt only if it needs it.

4. 4

   Prepare the bonito

   Keep the bonito refrigerated until the sauce is ready. Cut it across the grain into 8 pieces about 2.5cm thick, trimming away every strip of dark bloodline, which tastes stronger and can make the sauce muddy. Pat the pieces thoroughly dry and season them evenly with the remaining 4g salt. Pésalo, no lo adivines, weigh it, don't guess.

5. 5

   Sear it briefly

   Heat the remaining 20ml olive oil in a broad frying pan over medium-high heat. When the oil moves freely and glints, add the bonito in one uncrowded layer, working in two batches if necessary. Sear for 30 seconds on each broad side, no longer. The surfaces should turn pale and take a little colour while the centres remain raw. Transfer the pieces immediately to a plate.

6. 6

   Finish off heat

   Bring the tomato sauce to a steady gentle bubble. Slide in the bonito and any juices from the plate, turn each piece once to coat it, then cover the pan and take it off the heat immediately. Leave it undisturbed for 5 to 7 minutes. Check the thickest piece: the centre should be just opaque, moist, and ready to separate into broad flakes. If it is still cool and raw, return the covered pan to the lowest heat in 30-second intervals. For a fully cooked serving, check that the centre reaches 63°C. Spoon over plenty of sauce and serve without boiling the fish again.

   The sauce holds enough heat to finish the bonito. Boiling it in the sauce is not extra care; it is how good tuna becomes dry.

Chef Tips

• •Bonito del norte is albacore tuna. At an English-speaking fish counter, ask for a thick albacore loin rather than simply asking for bonito, which may bring you a darker, stronger fish. Good frozen albacore is preferable to tired fresh tuna; thaw it overnight in the refrigerator and dry it well.
• •The costera del bonito runs through the northern summer, when the fish is abundant and tomatoes are at their sweetest. That meeting of seasons is part of the dish. Outside it, frozen albacore and good canned whole tomatoes are the honest compromise.
• •Yellowfin tuna can stand in for albacore. Its flesh is darker, firmer, and a little less delicate, so keep the pieces thick and use exactly the same short cooking time.
• •This is a make-ahead dish because the sauce waits, not the fish. Cook the tomato sauce up to three days ahead, refrigerate it covered, and reheat it fully before searing and adding the bonito.
• •Serve it with plain bread for the sauce. Fried or boiled potatoes are also common alongside, but don't turn them into the sauce; then you're walking toward another dish.
• •A young txakoli from the Basque Country suits the sweet tomato and rich fish. Its clean acidity does the work without covering the bonito.
• •Leftovers keep for up to two days covered in the refrigerator. Warm them very gently and stop as soon as the sauce is hot; the bonito will be firmer than on the first day, and no reheating trick can give that tenderness back.

Advance Preparation

• •Make the tomato sauce up to three days ahead. Cool it promptly, cover, and refrigerate; bring it back to a full gentle simmer before adding the fish.
• •The tomato sauce can be frozen without the bonito for up to two months. Thaw it overnight in the refrigerator and reduce it for a few minutes if it releases water.
• •Trim and portion the bonito up to 12 hours ahead and keep it tightly covered in the coldest part of the refrigerator. Salt it only just before searing.
• •The completed dish can stand covered for 15 to 20 minutes before serving. Longer holding continues to firm the fish, so for the best texture, let the sauce do the waiting.

Frequently Asked Questions

Nutrition Information

1 serving (about 520g)