This recipe is like tacos - seasoned ground meat, cheese, lettuce, tomatoes - but instead of filling taco shells, it is baked into a casserole with a cornbread crust. So feel free to vary the ingredients here to suit your own taste in tacos. I almost always have a can of some type of beans in my pantry, and any type works well. If using the "chili hot beans" by Bush's, you don't even need to rinse and drain - the sauce works well, running down into the meat and cornbread. Then top the servings the way you like your tacos. I use this recipe when someone wants tacos and we don't have shells.
Preheat oven to 400°F. Prepare Jiffy cornbread mix according to package directions. Place into a greased shallow 2-quart casserole dish or 9x13" pan. Bake 15 minutes and remove from oven. Lower oven temperature to 350°F.
While cornbread is baking, brown ground beef and onions in a skillet, adding in the taco seasoning, and breaking meat up until it's very fine. Add any water called for with the taco seasoning and stir well. When the cornbread comes out of the oven, spread the seasoned meat mixture evenly over the cornbread.
Evenly distribute the black beans on top of the meat. Then top all with the 2 cups of cheese. Return casserole to oven, and continue baking about 10 minutes until cheese is melted.
Remove from oven and allow to rest 5 minutes before slicing into squares to serve. Top each serving with lettuce, tomatoes, sour cream, salsa, and green onions as desired.