Cheesy Beef Enchilada Casserole

1 lb. ground beef
2 cups salsa
1 can black beans, rinsed and drained
1/2 cup sour cream
3/4 cup frozen corn, rinsed and drained
1 Tbl. taco seasoning
1/4 tsp. cumin
1-1/2 cups grated cheese
sliced olives (optional)
Cilantro (optional)
Corn tortillas--depending on taste...cut into triangles
Diced tomato, sour cream, lettuce--for topping

Pre-heat oven to 375 degrees.  In large skillet (NOT non-stick), brown ground beef.  Stir in salsa, beans, sour cream, taco seasoning, corn, cumin, and cilantro (if desired).  Spread a thin layer of meat mixture (about 1/3 of the mixture) in the bottom of a greased casserole dish.  Then sprinkle about 1/2 cup cheese.  Next spread a layer of tortilla triangles.  Then do another layer of meat mixture (1/2 of the remaining mix), followed by 1/2 cup cheese.  Top with another layer of tortilla triangles, rest of meat, and top with final amount of cheese and sliced olives (if desired).  Bake until hot and bubbly (about 15-20 min.)  Serve with diced tomato, sour cream, and lettuce.