Preheat your oven to 350°F (175°C).

In a large skillet over medium heat, cook the ground beef and chopped onion until the beef is browned and the onion is soft, about 5-7 minutes. Drain any excess fat.

Stir in the black beans, diced tomatoes with green chilies, chili powder, cumin, garlic powder, salt, and black pepper. Simmer for 5 minutes.

In a separate bowl, combine the cornmeal, milk, and egg, mixing until smooth.

Grease a 9x13-inch baking dish. Pour half of the cornmeal mixture into the dish, spreading it evenly.

Layer the beef mixture over the cornmeal, then pour the remaining cornmeal mixture on top.

Sprinkle the shredded cheddar cheese and black olives over the top.

Bake in the preheated oven for 30-35 minutes, or until the top is golden brown and set.

Let it cool for 10 minutes before slicing. Garnish with chopped cilantro before serving.