1. Place the chicken in the bottom of the slow cooker.
2. In a small bowl, whisk together the lime juice, chicken broth, garlic, cumin, and red pepper flakes if using.
3. Season the chicken generously with salt and pepper, then pour the lime juice mixture over the chicken.
4. Sprinkle the chopped cilantro over the top of the chicken.
5. Cover and cook on low for 5-6 hours or on high for 2-3 hours, until the chicken is cooked through and tender.
6. Shred the chicken with two forks in the slow cooker and mix it into the juices.
7. Serve the chicken with the additional fresh cilantro and lime wedges on the side.
