Heat the olive oil in a large pot or Dutch oven over medium heat. Add the diced onion and cook for about 5 minutes until it becomes soft and translucent. Stir in the minced garlic and cook for another minute until fragrant, being careful not to burn it.
Pour in the chicken broth, red enchilada sauce, and diced tomatoes with green chilies. Stir in the ground cumin and chili powder. These spices will form the base of your bold Southwestern flavor profile.
Place the raw chicken breasts into the pot, ensuring they are fully submerged in the liquid. Bring the mixture to a gentle boil, then reduce the heat to low. Cover the pot and simmer for about 15 to 20 minutes, or until the chicken is cooked through and easy to shred.
Remove the chicken from the pot and place it on a cutting board. Use two forks to shred the meat into bite-sized pieces. Return the shredded chicken to the pot along with the black beans and corn. Let the soup simmer for another 5 to 10 minutes to allow the flavors to meld together.
Taste the soup and add salt and pepper as needed. If you want a bit more tang, you can squeeze in a little fresh lime juice at this stage. Ladle the hot soup into bowls and prepare for the best part—the toppings!