Cook onion and green pepper in fat until onions are yellow. Add and fry ground beef until mixture falls apart. Drain off any fat.
Stir in tomatoes, rice or noodles, chili powder, salt and pepper. Pour into greased 2-quart (8-inch) casserole dish.
Cover and bake at 350 degrees for 1 hour, removing cover for last 15 minutes of bake time and topping with grated cheese. Serve hot. Makes 6 servings.