Enchilada Casserole

1 can chili (no beans)
1 package Doritos
1 small onion (chopped fine)
2 cups shredded cheddar cheese

Spread Doritos on bottom of casserole dish. Heat chili and pour over Doritos. Sprinkle with onion, then cheese on top. Bake at 350 until cheese is melted (about 10 minutes).