Preheat your oven to 400°F (200°C).
In a skillet, brown the ground beef over medium heat until fully cooked.
Drain excess fat and stir in taco seasoning.
Add black beans, corn, and diced tomatoes; cook for 5 minutes.
In a bowl, whisk together milk and eggs.
In another bowl, combine cornmeal, flour, sugar, baking powder, and salt.
Mix the wet and dry ingredients until just combined.
Spread the beef mixture evenly in a greased baking dish.
Pour the cornbread batter over the beef mixture.
Bake for 25-30 minutes or until golden brown and a toothpick comes out clean.