With oven rack in center position, preheat oven to 350°F. Lightly grease or spray an 8-inch square baking dish with nonstick cooking spray.

Set a pot or large skillet over medium heat and cook ground beef until browned. Drain grease, stir in salsa and taco seasoning, and bring to a simmer. Cook for 5 minutes on low until thickened. Stir in black beans, corn, and black olives, and transfer mixture to prepared baking dish, spreading it in an even layer.

Prepare cornbread batter according to package directions, stirring in cheddar cheese and green chiles until just combined. Spread batter over beef mixture, smoothing to edges of dish. Bake, uncovered, for 30 to 35 minutes or until cornbread is golden brown and tests done with a toothpick.

Serve with sour cream, additional salsa, cheddar cheese, black olives, diced tomatoes, diced avocado, or your favorite garnishes.