1 lb. frankfurters
2 c. leftover mashed potatoes (may use instant)
1 egg, slightly beaten
6 slices American cheese

Split frankfurters in half lengthwise. Place half of frankfurters on cookie sheet, cut side up, with sides touching. Mix egg into potatoes and spread over frankfurters; top with 3 slices of cheese. Cover with tops of frankfurters. Top with remaining cheese. Secure with toothpicks. Bake at 400 degrees for 15- 20 minutes.