• 3 pounds fresh red tuna (or halibut, cod, or swordfish), cut in a thick slice as for a fish steak
• boiling water to cover
• salt
• 1 lemon, cut in half
• 12 anchovy fillets, cut in half
• 3 tablespoons olive oil
• 2 carrots, sliced thin
• 2 onions, sliced thin
• salt
• freshly ground black pepper
• 3 garlic cloves, minced
• ½ teaspoon fennel seed
• 1 cup sorrel leaves, chopped (optional)
• 4 leaves Boston or romaine lettuce, blanched and cut in strips
• 1 cup dry white wine

Blanch the slice of tuna in a pot of boiling water with salt and the lemon halves for 5 minutes and drain it. Because the fish has been cut crosswise, the flesh will have concentric rings—insert the anchovies between these rings by first making small cuts with a knife.

You can prepare this much ahead of time. Cover with plastic wrap and refrigerate until ready to cook. (The carrots, onions, and blanched lettuce can also be cut and kept covered and refrigerated.)

Heat the olive oil in a heavy-bottomed pan and add the carrots and onions. Lay the fish on them, sprinkle with salt and pepper, and cook over a medium flame for 10 minutes. Gently turn the fish over with two spatulas. Add the garlic and fennel seed. Cover with the sorrel and lettuce leaves and simmer for 10 minutes more. Add the wine and cook over a low flame for 20 to 30 minutes. Check the seasoning.

Place the fish in the center of a warm platter. Pile the carrots and onions at one end of the dish, the sorrel at the other end, and lettuce along the sides. Pour the juices over the fish and vegetables and season again with a little salt and pepper.