1 lg. onion, chopped
2 lbs. ground beef
2 cans cream of chicken soup
1 lg. pkg. Doritos (plain or taco)
2 cans pinto beans
1 can Ro-Tel tomatoes and green chili
American cheese

Brown beef and onions in skillet, drain fat. Add all other ingredients except cheese. Place crushed Doritos in 9x13 pyrex pan and pour mixture over the Doritos. Lay slices of cheese on top. Place in oven and bake at 400 until cheese melts and browns a little.