Mix all ingredients, except shrimp and onion, together in bowl.
Place shrimp in bowl and add marinade. Mix and marinate 1 hour.
Preheat barbecue at medium.
Alternate shrimp and onion on skewers.
Oil grill and add skewers. Cover and cook 3 to 4 minutes on each side. Season to taste and baste during cooking.
Serve with salad or rice.