In a large skillet, over medium-high heat, cook and crumble ground beef with the chopped onion until beef is brown and fully cooked. Drain any grease.
Add cumin, garlic powder, corn and black beans to skillet. Stir to combine and cook another 5 minutes or so to heat everything through.
Remove lettuce leaves and rinse with water; pat dry. Take each leaf and fill with 1/3 cup meat mixture. Top each taco lettuce wrap with tomato, cheese and any other toppings you desire. Serve and enjoy!