Season the chicken breasts with a pinch of salt and pepper, then cook in a large pot over medium heat with a tablespoon of olive oil until golden and cooked through, about 6-8 minutes per side. Remove, let cool slightly, then shred into bite-sized pieces.
Add the diced onion to the same pot, sautéing until translucent and fragrant, about 3-4 minutes. Stir in the minced garlic and cook for another 30 seconds until aromatic.
Pour in the diced tomatoes with their juices, stirring well to combine all the flavors. Let this mixture simmer for 3 minutes to develop the base taste.
Stir in the drained black beans, corn kernels, cumin, chili powder, and the shredded cooked chicken. Pour in the chicken broth, bringing everything to a gentle boil.
Reduce the heat to low and let the soup simmer uncovered for 20-25 minutes, stirring occasionally. During this time, the flavors meld and the soup thickens slightly.
Taste and adjust seasoning with additional salt and pepper as needed. Once the soup is flavorful and thickened, it’s ready to serve.
Ladle the hot soup into bowls, then top with crushed tortilla chips and slices of ripe avocado for added crunch and creaminess. Serve immediately and enjoy the hearty, layered flavors.