Cook noodles according to directions ground beef can substitute for sausage. Heat oil and saute' garlic and onions till tender.Add tomatoes, salt and pepper. Bring to a boil then cover and simmer over low heat 1 hour. Saute' sausage until brown. Discard fat.Mix ricotta and diced mozzarella cheese together in a bowl. Spread 1/2 cup sauce on bottom of baking pan.Arrange noodles with layer of cheese mixture, parmasen cheese, tomato sauce, and meat. Repeat proc- ess ending with layer of noodles and sauce. Bake in moderate oven (350 degrees) for 20 minutes, or until hot.