In a 5 quart stock pot, over medium-high heat and using a large wooden spoon to stir, brown the ground beef and onions until beef is completely cooked and the onions are translucent. Drain off any excess grease, and return to the stock pot.

Reduce the heat to medium and add the garlic. Stir often to keep the garlic from burning. Cook for 1 - 2 minutes.

Stir in the diced petite tomatoes, do not drain the juice.

Stir in the chili powder, ground cumin, dried oregano leaves, black pepper and kosher salt. Continue stirring until all the ingredients are well combined. Continue to cook for 5 minutes.

Add the rinsed and drained black beans, dark red kidney beans and the mexicorn. Stir until the beans and corn are combined. Reduce the heat to low and simmer for 5 more minutes.

While the chili is simmering, preheat the oven to 375*, and lightly spray a 9x13 baking dish with nonstick spray.

Prepare the cornbread packets according to the directions. Pour the cornbread batter into the prepared baking dish. Using a silicone spatula, spread the cornbread evenly on the bottom and up a bit up the sides of the baking dish.

Remove the chili from the stovetop and carefully ladle the chili on top of cornbread. Bake for 20 minutes. Remove from the oven and sprinkle with the shredded cheese. Return to the oven and bake for another 5 minutes or until the cornbread is lightly golden and the cheese is completely melted.

Remove the casserole from the oven and evenly sprinkle the sliced green onion and cilantro over the top of the casserole.