In a medium-sized mixing bowl, combine the pureed mango, fresh lime juice, honey, olive oil, minced garlic, ground cumin, chili powder, salt, and pepper. Whisk together until the marinade is well blended and smooth.
Place the chicken breasts into a large resealable plastic bag or a shallow glass dish. Pour the mango-lime marinade over the chicken, ensuring that each piece is thoroughly coated in the flavorful mixture. Seal the bag tightly or cover the dish with plastic wrap, and refrigerate for a minimum of 1 hour; for even more robust flavors, marinate for up to 4 hours.
When ready to cook, preheat your grill to a medium-high temperature, approximately 375°F to 400°F (190°C to 200°C).
Remove the chicken from the marinade, allowing any excess to drip off. Discard the remaining marinade for food safety reasons.
Carefully place the chicken breasts onto the preheated grill. Grill for 6 to 7 minutes on each side, or until the chicken reaches an internal temperature of 165°F (75°C) and has beautiful grill marks forming on the surface.
Once the chicken is fully cooked, remove it from the grill and let it rest on a cutting board for about 5 minutes. This will allow the juices to redistribute, keeping the chicken tender.
Slice the grilled chicken into strips for serving. Add a generous sprinkle of freshly chopped cilantro on top for a burst of color and flavor.
Notes
For best results, marinate the chicken for up to 4 hours.