Thread shrimp onto skewers. (If using wooden skewers, soak in water for at least 15 minutes.) Place shrimp in a 13 x 9-inch baking dish with chicken breasts. Combine Spicy Marinade ingredients in a small bowl and mix well; pour over skewered shrimp and chicken, turning to coat well. Cover and refrigerate at least 2 hours or up to 24 hours, turning occasionally.
About 30 minutes before serving, preheat grill to medium and place rack 5 to 6 inches above heat. Grill shrimp 3 to 4 minutes, turning once; grill chicken breasts 6 minutes, turning once. Or, preheat broiler and broil shrimp and chicken 4 inches from heat as directed.
Makes 4 servings.