I made this last night and it was really easy and good! I did make some variations to the ingredients, which I will post below the recipe.

Mexican Casserole
1 pd ground beef
1/2 cup chopped onion
2 (8 oz) cans tomato sauce
3/4 Tbl chili powder
1 tsp salt
1 dozen tortillas, cut in half
2 cups shredded sharp cheddar cheese

Brown ground beef and onion; drain off fat. Stir in the tomato sauce, chili powder, and salt. In 1 1/2 qt casserole dish, place alternate layers of meat sauce, tortillas, and cheese, ending with cheese. Bake at 325 degrees for 45 minutes.

Variations: I used 1/2 Tbl chili powder, 1/2 tsp cumin, 1 tsp salt, and a pinch of cayenne pepper for a kick. I was in a hurry so I baked it at 350 for 30 minutes and it turned out fine. We had sour cream and green onions on top.