Preheat oven to 375˚F.
Place chicken breasts in a large mixing bowl and season with garlic powder, chili powder, salt, pepper, parsley, and olive oil. Mix until well combined.
Transfer the chicken breasts to a baking dish in a single layer.
Bake for 35 minutes or until thoroughly cooked. Cooking time will depend on the size of the chicken breasts.
In the meantime, work on the soup; heat the olive oil and butter in a large pot set over medium-low heat.
Add the onions, carrots, and parsley, and season with salt and pepper.
Cook for 5 minutes or until vegetables are tender, stirring frequently.
Stir in the bell peppers, jalapeño, and garlic, and continue to cook for another 4 to 5 minutes or until the peppers are tender.
Remove the cooked chicken from the oven; let it rest for a few minutes then cut it into cubes or shred it.
Transfer the chicken to the soup pot.
Stir in the tomatoes and black beans and season with chili powder, paprika, and cumin.
Add the chicken stock and bring the soup to a boil over medium-high heat.
Turn down to a simmer and continue to cook for an additional 10 minutes.
Taste for salt and pepper; adjust accordingly.
Ladle the soup into bowls and garnish it with tortilla chips and avocado slices.
Serve.