For the casserole: If you're using meat, brown it, drain the fat, add a little water & add taco seasoning. I've done it with or without meat - it's good both ways. Add all other ingredients to pan & heat those up. Dump in the bottom of a greased casserole dish.
For the Cornbread Topping: Mix together liquids, and then add dry ingredients. Dump this on top of the bean mixture and bake at 350 for 30 minutes.