Mom's Enchilada Pie Recipe

My mom cut this out of a newspaper years ago and has been fixing this recipe ever since. It is fattening as heck, but it always reminds me of home.

ENCHILADA PIE

1/4 cup oil
1 large onion, chopped
1 or 2 cloves garlic, minced
1 1/2 pounds ground beef
2 tablespoons flour
2 cans (8 ounces each) tomato sauce
1 cup water
2 tablespoons vinegar
1 cup chopped ripe olives
2 tablespoons chili powder
Salt and pepper to taste
6 corn tortillas
1 cup sharp cheese, grated (I use whatever I have on hand)

Saute onion and garlic in oil until lightly browned.  Add meat;
 cook and stir until brown. Sprinkle flour on top of meat. 
Add tomato sauce, water, vinegar, olives, chili powder, salt
and pepper; simmer 20 minutes, stirring occasionally.

Cover bottom of a greased casserole with some of the meat
 sauce.  Add tortillas, meat sauce and grated cheese in
layers, ending with cheese on the top.  Bake at 350 degrees
 for 45 minutes.