2 cans tuna or 2 c. cooked chicken
1 can cream of mushroom soup
1 can Rotel tomatoes
1 lg. onion, chopped
1 lg. bag Doritos, crushed
1 can cream of chicken soup

Combine all but Doritos. Grease casserole dish and put half of Doritos in dish. Add half of mixture and rest of Doritos, then other half of mixture. Cover with grated cheese. Bake 45 minutes at 350 degrees.