Heat 2 tablespoons of the olive oil in a saucepan, add the onion and garlic, and cook over medium heat until the onion is soft. Add the tomatoes with their juice, celery, sugar, and season to taste, and stir together to break up the tomatoes. Simmer this tomato sauce for 15 minutes.
While the sauce is cooking, heat the remaining oil in a frying pan and fry the tuna steaks for 4-5 minutes on either side until lightly browned. Place the steaks in a lightly oiled ovenproof dish.
Add the capers, olives, and parsley to the sauce, stir, and pour over the fish. Bake in a
© 1999 Jennifer Paterson and Clarissa Dickson Wright estate. All rights reserved.