In a non-metallic bowl, combine chicken broth, orange juice concentrate, vinegar, 1 Tbsp Jerk seasoning and garlic. Place duck breasts in a plastic bag and pour half of marinade mixture into bag. Refrigerate for 12 hours. Refrigerate remaining marinade. Combine the remaining chilled marinade mixture with cornstarch. Bring to a boil in a saucepan. Reduce heat and simmer for 2 minutes while stirring. Cool mixture.
Remove duck from marinade and pat dry. Rub duck with olive oil and Jerk seasoning. Place on white-hot grill and cook until medium-rare. Just before removing from the grill, baste with thickened sauce mixture. Allow to rest for a few minutes, slice and top with fruit segments, onions and zest.
Servings: 6