Heat the olive oil in a large Dutch oven or other heavy pot over medium heat.
Add the onion and cook for 3 minutes, stirring often, until the onion starts to soften.
Add the garlic and cook, stirring, for 30 seconds.
Add the broth, enchilada sauce, fire roasted diced tomatoes, diced green chiles, chili powder, cumin, dried oregano, black beans and pinto beans. Stir.
Nestle the chicken into the liquid in the pot.
Bring the pot to a simmer. Then cover the pot and cook at a medium simmer (reduce the heat as needed) for 20-25 minutes, until the chicken is cooked through to 165° F.
Remove the chicken from the soup and place it on a clean cutting board to rest for a few minutes. Then shred the chicken.
Meanwhile, stir the corn into the soup. Simmer, covered, for 5 minutes. Stir the shredded chicken back into the soup. Serve soup with toppings as desired.