In a large pot, heat the olive oil over medium heat. Once hot, add the diced onion and bell pepper, sautéing for 4-5 minutes until they begin to soften and become translucent.
Stir in the minced garlic and cook for an additional 1-2 minutes until the aroma fills the kitchen, being careful not to burn the garlic.
Add the chicken breasts to the pot along with the chicken broth, diced tomatoes, black beans, corn, and ground cumin. Stir everything together so the flavors meld.
Raise the heat to bring the mixture to a gentle boil. Once boiling, reduce the heat to low, cover the pot, and let it simmer for about 20-25 minutes, or until the chicken is fully cooked (internal temperature should reach 165°F).
Carefully remove the chicken from the pot. Using two forks, shred it into bite-sized pieces, then return the shredded chicken to the soup, stirring to incorporate.
Stir in the lime juice and zest, seasoning the soup with salt and pepper to your liking. Adjust flavors as necessary.
Just before serving, fold in the chopped cilantro, allowing its fresh flavor to infuse the soup.
Notes
For added crunch, serve with tortilla chips or drizzle with sour cream.