Heat the olive oil in a large skillet over medium heat. Add the ground beef and cook until browned, split it into small pieces as it cooks.
Add the chopped onion and bell peppers and cook until the vegetables are tender about 5 minutes.
Add the corn, black beans, garlic powder, cumin, chili powder, salt, and black pepper. Stir to combine and continue to cook for an additional 6 minutes.
Arrange the chopped lettuce on a large platter. Spoon the beef mixture over the lettuce. Top with diced avocado, shredded cheese, salsa, and sour cream.
Serve with tortilla chips on the side.