Preheat oven to 350 degrees
Spray a square 10x10 inch casserole dish with cooking oil
In a large skillet, brown the ground beef with the chopped onions
If needed - drain any grease. If you used sirloin, you probably won't have any to drain
Stir in the salsa, taco seasoning and water
Cook until thick - just a few minutes
Add the drained corn and drained sliced olives - stir in
Pour the mixture into your casserole dish
In a large bowl, mix the cornmeal, flour, sugar, baking powder, and salt
In another bowl, mix the oil, milk and egg
Mix the wet and dry cornbread ingredients together
Add the cheese and chiles into the cornbread mixture and stir those in
Spread the cornmeal mixture over the meat mixture
Bake for about 35 minutes - check corn bread for doneness by inserting a toothpick in. If it comes out dry, you're good to go
Optional serving suggestions: sour cream and cilantro