Preparation:
Cut the onions in thin slivers and sauté them in the olive oil and butter. Add salt and cook, stirring, until the slivers are limp. (This process can be speeded up by adding 1/4 cup of warm water and letting it evaporate completely.) Stir in the vinegar and sugar and cook over low heat, stirring, until the vinegar has evaporated. Add the red pepper and the drained raisins, stir, and turn off the heat. The sauce should retain the texture of the slivers and have enough moisture to be spoonable. Cover the pan and keep the sauce warm.
To make the fish, put olive oil, butter, and bay leaves in a large sauté pan. When warm, not hot, add the tuna steaks. Salt and pepper to taste and sauté 2 to 3 minutes per side, depending on thickness. Do not overcook; tuna tends to dry out. The steaks should be cooked outside but still moist inside. Raise the heat, add the wine, and cover the pan for a second or two, until the wine has stopped steaming. Uncover, cook a moment longer, and transfer the steaks with their pan sauce to warm serving plates. Spoon over them the warm onion sauce and serve.
Comments: In a classic dish of the Aegadian Islands, off the western coast of Sicily, fresh tuna steaks are pan-cooked, kept moist, and enriched by a sweet-sour onion sauce. |