One day before serving - Whisk the 4 marinade ingredients together. Place the chicken breasts in a heavy zip top plastic bag. Add the marinade, seal and refrigerate overnight, turning the bag over a few times.
Also, one day before serving, prepare the salsa mixture - In a bowl, mix the pineapple chunks, mango, red pepper, green onions and garlic together. Whisk the lime juice and honey together. Pour over the pineapple mixture and stir to mix well. Cover tightly and refrigerate overnight.
Grilling - Just before grilling, bring the salsa to room temperature. Grill the chicken breasts over medium hot coals for 30 to 40 minutes, turning over about half way through the grilling time. The chicken is done when it is tender, nicely browned, and juices run clear.
Gently heat the prepared salsa. (Do not cook or boil.) Top each grilled chicken breast half with salsa just before serving.