Enchilada Pie

1 lb. hamburger
1/2 cup onion chopped
2 tsp. salt
1/4 tsp pepper
1 TBSP chili powder
1 (8oz) can tomato sauce
6 tortillas, buttered
1 1/2 lb grated cheese
1 cup water

Brown hamburger and onion. Add seasonings and sauce. In 2 quart casserole, alternate tortillas, meat sauce and cheese. Add water. Cover and bake at 400* for 20 minutes.