Place wooden skewers in water and allow to soak for at least 1 hour (let them soak overnight for best results).
For the Sauce/marinade:
Place all sauce ingredients in a blender and puree until smooth. Reserve 1 cup sauce for serving.
In a large bowl, combine chicken and remaining sauce. Let the chicken marinate at least 15 minutes (or several hours if making ahead of time).
Grease/oil grill before turning on. While grill is heating up, skewer chicken. Discard marinade that is in the bottom of the bowl.
Grill over high heat for about 3 minutes per side or until browned. Brush with some of the 1 cup reserved sauce and then serve over coconut rice with extra sauce and sliced mangoes.