Add about 2-3 cups of water to a pot and place over medium heat. When water is almost boiling add chicken breasts and cook for 15-20 minutes.
Remove from pot and shred chicken pulling apart with two forks.
While chicken is cooking you can start preparing soup.
Add 2 tablespoons of oil to a pot over medium heat. Add chopped onions and stir. Let onions cook until they are translucent. Then proceed to add chopped garlic and cook for another minute stirring garlic and onions around pot with a spoon.
Add the chicken broth, can of veggie mix, cilantro and cayenne pepper. Lower heat and cook together for 10 minutes.
Add a little bit of salt to taste. Taste soup and see if would like more salt.
Add shredded chicken to soup and cook for another 10 minutes.
Serve soup in bowls and top with avocado cubes.
You can also add more chopped cilantro if you really enjoy the cilantro flavor in your soup like I do.