In a medium bowl, combine the diced mango, red chili, lime juice, honey, olive oil, and minced garlic to create a marinade. Blend until smooth but still slightly chunky.
Season the chicken breasts with salt and pepper and place them in a resealable plastic bag. Pour the marinade over the chicken, seal the bag, and massage the marinade into the chicken. Refrigerate for at least 30 minutes (up to 2 hours for more flavor).
Preheat your grill or a grill pan over medium-high heat.
Remove the chicken from the marinade and let any excess drip off. Discard the remaining marinade.
Grill the chicken for about 6-7 minutes on each side or until the internal temperature reaches 165°F (75°C) and the chicken is golden brown with nice grill marks.
Once cooked, let the chicken rest for 5 minutes before slicing.
Serve the sliced chicken on a plate, drizzled with any juice collected during resting and garnish with fresh cilantro.
Notes
Adjust the amount of chili based on your spice preference.