1 (10 3/4 oz.) mushroom soup
1/2 c. milk
1 (6 1/2 oz.) can tuna, drained
1 1/4 c. crushed potato chips
1 c. cooked green peas
1/2 c. chopped onion

Mix soup and milk in ungreased 1 quart casserole. Stir in tuna, 1 cup chips, peas and onion. Sprinkle with remaining chips. Bake uncovered in 350 degree oven until hot, about 25 minutes.