1 (7 oz.) can tuna, flaked
1 c. celery, chopped
1 sm. onion, minced
1/2 c. American cheese, cubed
1/4 c. mayonnaise
Salt & pepper
6 hamburger buns

Mix tuna, celery, onion, American cheese, mayonnaise and pepper. Split hamburger buns and butter. Fill buns with tuna mixture. Place in foil and fold airtight. Just before serving, heat oven to 350 degrees; bake 15 to 20 minutes.