This method of cooking is often used for cod, but I haven't seen many recipes for tuna which don't involve either frying or grilling it, so this makes a nice change.
Serves two.
Heat oven to gas mark 6. Gently fry the garlic, pepper and courgette in the olive oil for 10 minutes till soft. Add the chopped tomatoes and puree, bring to the boil and cook gently for another five minutes. Stir in the chopped olives. Spread a small quantity of this sauce over the bottom of a greased ovenproof dish, then lay the tuna steaks on top and cover them with the rest of the sauce. Cover the dish in foil and bake for 30 minutes, while you cook some rice to go with it.