How to Make It
In a small bowl, using a fork, blend the butter with the jalapeño, lime zest, 1 teaspoon of salt and 1/2 teaspoon of pepper.
Using scissors, cut along the back of each shrimp and scrape out the vein. Gently open the shell without breaking it off and, using a thin offset spatula or knife, spread some of the butter on both sides of each shrimp. Transfer the shrimp to a baking sheet and refrigerate for 30 minutes.
Light a grill. Season the shrimp lightly with salt and pepper. Grill over high heat, turning, until lightly charred and just cooked through, about 4 minutes. Transfer the shrimp to a platter and serve with chopped cilantro and lime wedges.