Preheat your oven to 375°F (190°C) and lightly grease a 9×13-inch baking dish.

In a large skillet over medium heat, cook the ground beef until browned for about 5–7 minutes. Drain excess fat.

Add chopped onion and minced garlic to the skillet and sauté for 3–4 minutes until the onion is translucent.

Mix in the tomato sauce, ketchup, Worcestershire sauce, brown sugar, yellow mustard, salt, and black pepper. Simmer for 5–7 minutes until slightly thickened.

Spread the beef mixture evenly in the greased baking dish.

In a mixing bowl, combine the cornbread mix, eggs, and milk. Mix until just combined. Fold in the cheddar cheese.

Pour the cornbread batter over the beef mixture and spread gently to cover the meat completely.

Bake in the preheated oven for 25–30 minutes, until golden brown and a toothpick comes out clean.

Let the casserole cool for about 5–10 minutes before serving.