In a large bowl, toss the Large Shrimp (1.5 pound) with Olive Oil (2 tablespoon), Kosher Salt (1 teaspoon), and Ground Black Pepper (1/2 teaspoon). Cover and refrigerate until ready to use.
Combine the Scallion (3 stalk) and Red Wine Vinegar (4 tablespoon) in a 2-cup glass measuring cup or medium bowl. Let the scallions sit in the vinegar for 15 minutes.
Add the Fresh Parsley (3/4 cup), Fresh Mint (1/2 cup), Garlic (1 clove), Capers (1 1/2 tablespoon), and Kosher Salt (1/2 teaspoon) and stir to combine. Add Olive Oil (9 tablespoon) (1/2 cup plus 1 Tbsp). Mix well and set aside.
Prepare a charcoal grill with hot coals, or set a gas grill to medium-high heat, then brush the grilling rack with oil to prevent the shrimp from sticking. Skewer the shrimp.
Grill the shrimp for 1-1/2 minutes on each side, and serve immediately with the Scallion Salsa Verde. Serve and enjoy!