Mince garlic. Heat skillet over medium heat and add oil and garlic. Sauté for 1 minute.
Add beef and brown until crumbled and no longer pink, 6-7 minutes.
Add quinoa, broth, rinsed and drained beans, tomatoes, corn, chili powder, cumin, salt, and pepper. Bring to a boil, cover, and simmer for 15 minutes. Add more broth if quinoa is still raw after 15 minutes.
Cube avocado and serve over quinoa with mango cubes on the side.