Hot Beef Hoagies

2 T. butter
1 lb. top sirloin steak, thinly sliced
1/2 c. thinly sliced onion
1 c. thinly sliced green pepper
salt and pepper to taste
1 c. grated mozzarella cheese
4 hoagie buns (toasted if desired)

In a frying pan, melt the butter. Add steak slices and cook and stir over medium heat until cooked through and browned (about 10 minutes). Add onion and green peppers. Stir-fry about 5 minutes or until vegetables are tender. Salt and pepper to taste. Remove pan from heat. Place grated cheese over top of meat and vegetables. Put lid on. Allow cheese to melt (about 5 minutes). Spoon mixture on hoagie buns. Enjoy!