1 lb ground beef, browned
2 tsp minced onion
1 tsp Italian seasoning
¾ cup ketchup
½ cup slice olives
½ lb. mozzarella cheese, grated

Simmer first five ingredients for 5 minutes.  Cool slightly; stir in cheese.  Serve on buns.  You can make a big batch and freeze the leftovers sandwiches for a quick snack later.