1 (10 1/2 oz.) can condensed cream of mushroom soup
3/4 c. milk
2 tsp. finely minced onion
Salt and pepper to taste
3 c. coarsely crushed potato chips
1 (6 oz.) can tuna

Blend mushroom soup and milk; add onion. Bring slowly to boiling point, stirring constantly. Season to taste with salt and pepper. Arrange half of the potato chips in bottom of casserole dish. Top with half of tuna. Repeat layers. Pour soup mixture over all and garnish top with whole potato chips. Bake at 350 degrees for 25 minutes.