Place the chicken breasts in the bottom of a slow cooker.
Top with all the remaining ingredients and season generously with sea salt and freshly ground black pepper.
Cover and cook on low 6 to 8 hours, or high 4 to 5 hours.
Once chicken is cooked through and no longer pink, remove from slow cooker.
Shred the chicken with a fork and mix well.
Serve topped with fresh cilantro and avocado.