Heat a large skillet over medium heat. Add ground turkey. Cook ground turkey until it has browned, crumbling as it cooks. Stir in black beans. Add garlic, chili powder, oregano, cumin and salt. Stir. Add broth and salsa. Reduce heat and cook for 10- 15 minutes or until mixture has thickened.
Split each hamburger bun. Top each with turkey mixture, ½ cup of corn, ¼ cup of cheese, ¼ cup of lettuce, tomatoes and avocado.