Brown the ground beef over med-high heat in a large oven-proof skillet until no pink remains, drain. Add the uncooked pasta, taco Seasoning, both cans tomatoes with chilies, and water to the browned beef.
Bring the mixture to a boil, lower heat, cover and simmer over low heat for 20 minutes until pasta is cooked and liquid is absorbed.. Stir occasionally. Add the shredded cheese and stir until cheese is melted.
In a small bowl, stir the cornbread mix, egg and milk until well blended. Drop by spoonfuls onto the taco/pasta mixture. Most of the taco mixture should be covered.
Bake for 20 minutes, until the cornbread topping is golden brown.