Step 1: Prepare the Chili Base: In a large skillet, brown the ground beef over medium heat. Drain off any excess grease.
Step 2: Combine Chili Ingredients: Stir in the chili beans, tomato sauce, diced tomatoes and green chilies, and chili seasoning. Bring to a simmer and cook for 10 minutes, stirring occasionally, to allow the flavors to meld.
Step 3: Prepare the Cornbread Topping: While the chili simmers, prepare the cornbread topping. In a medium bowl, combine the Jiffy Corn Muffin Mix, milk, and egg. Stir until just combined; do not overmix.
Step 4: Assemble the Casserole: Pour the chili mixture into a 9x13 inch baking dish. Evenly spread the cornbread batter over the top of the chili.
Step 5: Bake the Casserole: If desired, sprinkle the shredded cheddar cheese over the cornbread topping. Bake in a preheated oven at 375F (190C) for 25-30 minutes, or until the cornbread is golden brown and a toothpick inserted into the center comes out clean.
Step 6: Cool and Serve: Let the casserole cool for a few minutes before serving.
Optional: For a spicier chili, add a pinch of cayenne pepper or a dash of hot sauce. To add more vegetables, stir in diced onions, bell peppers, or corn to the chili mixture. For a richer cornbread, melt 2 tablespoons of butter and add it to the cornbread batter.