In a large saucepan or Dutch oven, brown ground beef with onions, green peppers and garlic powder. Drain fat. Return to pan. Add tomatoes, with their juice and salt and pepper to taste. Simmer covered for 45 minutes to an hour. Stir in cooked shells. Heat through. Serve piping hot with grated parmesan cheese.

* I am not a green pepper fan and this is the only dish that has green peppers in it that I'll eat. Childhood eating experiences do weird things to one's adult palate, don't they?