1 (4 oz.) can shoestring potatoes
1 can condensed cream of mushroom soup
1 (6 to 9 oz.) can tuna, drained
1 (6 oz.) can (2/3 c.) evaporated milk
1 (3 oz.) can sliced mushrooms, drained
1/4 c. chopped pimento

Reserve 1 cup of shoestring potatoes for topper. Combine remaining potatoes with the other ingredients. Pour into 1 1/2 quart casserole. Arrange reserved potatoes on top. Bake uncovered in moderate oven at 375 degrees for 20 to 25 minutes.