PREPARATION
Process first 6 ingredients in a food processor or blender until smooth. Combine garlic mixture and olive oil in a medium saucepan and bring to a boil. Reduce heat and simmer about 1 minute, stirring occasionally. Remove from heat and stir in sour orange juice and cilantro; let cool.
Combine chicken and 1 cup marinade in a large shallow nonaluminum baking dish or plastic bag; turn to coat. Cover, or close bag, and marinate in refrigerator about 3 hours. Refrigerate remaining marinade.
Remove chicken from marinade, discarding marinade. Grill or broil chicken about 20 minutes, brushing frequently with reserved marinade, or until chicken is thoroughly cooked, turning occasionally.