1. Using a sharp knife, carefully butterfly shrimp, cutting shrimp through the shell (start just above the tail, and cut through the middle of the shrimp until you reach the end) and removing the vein. Flatten shrimp with the palm of your hand. The shrimps should lie flat.
2. Mix Garlic Sauce ingredients together. Marinade shrimp in Garlic Sauce for 20 minutes. Lightly oil a large piece of aluminum foil.
3. Place shrimp in a single layer on top of foil. Grill until just cooked through, flipping shrimp halfway through cooking, about 3-4 minutes per side.