Preheat oven to 350 degrees F. In a large skillet cook lamb, onions, and garlic over medium heat until meat is brown and onions are tender, using a wooden spoon to break up meat as it cooks. Drain off fat.
Return meat to skillet. Add tomato sauce, diced tomatoes, tomato paste, olives, oregano, basil, sugar, and crushed red pepper; mix well. Transfer to two ungreased 1-quart casseroles or au gratin dishes or one 2-quart casserole or au gratin dish. Sprinkle with Parmesan. Bake, uncovered, for 20 to 25 minutes or until heated through. Serve with toasted bread slices.