Preheat oven to 350 degrees. Spray a large casserole dish with non-stick cooking spray and set aside.
In a large bowl, mix together the cornbread mix, creamed corn, green chilies, milk, egg, and 1 tablespoon of the taco seasoning. Mix until well combined and pour into the casserole dish. Bake for 30 minutes.
Meanwhile, in a medium sized pan, brown the ground beef and drain the excess fat. Add the remaining taco seasoning and water and cook until bubbly. Remove from heat.
After the cornbread is cooked, remove from oven and top with the ground beef, taco sauce, and 1 cup of cheese. Return to the oven and bake for 15 minutes. Remove from oven and top with shredded lettuce, tomatoes, and remaining cheese. Serve immediately.