1 can tuna
1 c. chopped celery
1/2 c. cubed American cheese
1 sm. onion, optional
1/4 c. mayonnaise
Salt & pepper

Mix ingredients in bowl. Spread 6 split buns with soft butter. Fill buns with tuna mixture. Wrap in foil and place on baking sheet. Bake 15 minutes at 350 degrees.