Heat the olive oil in a medium pot over medium heat.
Add the diced onion and bell pepper, sautéing for 3-4 minutes until softened.
Stir in the minced garlic, cumin, and chili powder, cooking for 1 minute until fragrant.
Pour in the chicken broth, diced tomatoes, and black beans. Season with sea salt and black pepper.
Add the whole chicken breast to the pot. Bring to a boil, then reduce heat and simmer for 15-20 minutes until the chicken is cooked through.
While the soup simmers, slice the corn tortilla into thin strips and toast them in a dry skillet or air fryer until crispy.
Remove the chicken from the pot, shred it using two forks, and return it to the soup.
Stir in the lime juice and fresh cilantro.
Ladle the soup into a bowl and garnish with the crispy tortilla strips and sliced avocado.