In a shallow pan, whisk together first 6 ingredients except chicken breasts. Remove and reserve 1/4 normal cup of the marinade. Coat chicken in the remaining marinade in the pan. Cover and refrigerate for several hours or at least 1 hour.
Preheat charcoal grill. Prepare Blueberry Chutney Sauce (see below). Place chicken breast 5 to 6 inches over medium-hot coals. Cook about 6 minutes on each side or until juices run clear and chicken is no longer pink inside. Baste once with reserved marinade towards end of cooking time for final glaze. Serve each piece of chicken with 2 or 3 spoonfuls of the Blueberry Chutney Sauce. Garnish with orange slices.
For the blueberry sauce: In a medium saucepan, heat oil. Saut'e onion 2 minutes or until soft. Add the remaining ingredients, including reserved grated rind of orange. Simmer over low, stirring often, 15 minutes or until mixture thickens slightly and the blueberries become soft. Use at once or cool and refrigerate. Rewarm as needed.