In a large pot, heat a splash of oil over medium heat.
Add the diced onion and sauté until translucent.
Stir in the minced garlic and cook for another minute.
Pour in the diced tomatoes and enchilada sauce, stirring to combine.
Add the chicken broth and bring to a simmer.
Mix in the shredded chicken, corn, and black beans.
Season with cumin, chili powder, salt, and pepper.
Let the soup simmer for about 20 minutes.
Taste and adjust seasoning as needed.
Serve hot, topped with cheese, sour cream, and cilantro.