1. Put the mangoes, cilantro, Truvia® natural sweetener, hot sauce, vinegar, coconut milk, onion, ginger, garlic, lime juice and zest and oil in a food processor and puree until smooth; add some water if too thick. Add salt and pepper to taste. You should have about 1 quart of marinade. Divide it in half.
2. Place the chicken and half the mango mixture in a plastic bag and rub to coat the chicken with the mango puree. Refrigerate at least 6 to 8 hours to marinate.
3. Put the other half of the mango mixture into a small saucepan with the water and simmer over low heat until thick, up to 20 minutes.
4. Preheat the grill to medium-high heat. Spray grill with cooking spray to prevent sticking. Remove the chicken from marinade, season with salt and pepper, and begin to grill slowly. Turn heat down to medium and cook for about 20 minutes, basting chicken constantly with remaining marinade. Discard marinade that was in contact with raw chicken; for the last 10 minutes of cooking, use only the stove sauce to baste the chicken. Cook chicken to an internal temperature of 165 degrees F.
5. Spoon some of the remaining marinade over the chicken as a sauce if needed.