Nutrition per serving may change if servings are adjusted.
16 fresh or frozen jumbo shrimp in shells (about 12 ounces)
3 to 4 cloves garlic, minced
1 tablespoon butter
¼ cup chopped fresh basil
1 tablespoon white balsamic vinegar
⅛ teaspoon salt
Fresh watercress or parsley (optional)
Thaw shrimp, if frozen. Rinse the shrimp; pat dry with paper towels.
Preheat broiler. Using a sharp paring knife, split each shrimp down the back through the shell almost all the way through the meaty portion, leaving the legs intact. Devein the shrimp. Loosen the shrimp from the shell by running the knife between the shell and the shrimp meat. Flatten the shrimp with your hand or the flat side of the blade. (Or remove the shell, leaving the tail intact and flatten with your hand or the knife blade.) Arrange the prepared shrimp, split sides up, in a single layer on a broiler pan.
Meanwhile, cook garlic in a small saucepan in hot butter until tender. Stir in basil, white balsamic vinegar, and salt.
Brush the shrimp with the garlic mixture. Broil the shrimp 3 to 4 inches from the heat for 5 to 8 minutes or just until the shrimp are opaque. Transfer the shrimp to a platter. If desired, surround with watercress or parsley.
To make ahead: Prepare as directed through Step 2. Cover and chill for up to 6 hours. Continue as directed in Steps 3 & 4.