How to Make It
Using kitchen scissors, cut down the back of each shrimp through the shell and halfway through the meat. Remove the dark veins and transfer the shrimp in their shells to a large bowl.
In a mortar or food processor, crush the garlic, ginger, oregano, sage, cilantro, crushed red pepper and lemon zest with 1 teaspoon of kosher salt until a coarse paste forms. Stir in the 1/2 cup of olive oil. Pour the mixture over the shrimp and toss to coat thoroughly. Let stand at room temperature for 1 hour.
Light a grill. Grill the shrimp over moderately high heat, turning once, until white throughout, about 4 minutes. Transfer the grilled shrimp to plates. Squeeze the lemon halves over the shrimp, drizzle with olive oil, season lightly with salt and pepper and serve at once.