Grilled Shrimp with Tamarind Sauce

Ingredients

 * 1 1/2 lb jumbo (8 to 12 per lb) shrimp
 * 3 teaspoons sea salt dissolved in 11/2 cups water

For tamarind sauce


 * 1 tablespoon tamarind from a pliable block
 * 1/3 cup water
 * 1 tablespoon peanut oil
 * 1 tablespoon chopped cleaned fresh cilantro roots and/or stems, pounded to a paste
 * 1 tablespoon minced garlic
 * 1 tablespoon Sriracha or other Asian hot chile sauce
 * 1 1/2 tablespoons palm sugar, or to taste
 * 1 tablespoon Asian fish sauce (preferably Thai naam pla), or to taste

Garnish:

2 fresh serrano or jalapeٌo chiles, seeded, halved lengthwise, and finely cut crosswise; and fresh cilantro sprigs

Directions
Prepare grill for cooking.

Soak shrimp (still in shells) in salt water 5 minutes, then rinse well in a colander.

Make sauce: Place tamarind in a bowl with water and rub with your fingers to dissolve pulp. Pour through a strainer into a bowl, pressing hard on solids, and discard solids.

Heat oil in a small heavy saucepan over moderate heat until hot but not smoking, then cook cilantro paste and garlic, stirring, until fragrant. Stir in hot sauce, 3 tablespoons tamarind juice, palm sugar, and fish sauce. Simmer until thickened to consistency of light syrup, about 3 minutes.

Grill shrimp: Snip shells of shrimp with scissors down center of back, from wide end to second-to-last tail section. Butterfly shrimp in their shells, making a deep incision along length of back where shells are cut, and devein.

Grill shrimp on their sides on an oiled rack set 5 to 6 inches over glowing coals until shells are pink and slightly charred and shrimp are just cooked through, 3 to 4 minutes on each side. (Alternatively, grill shrimp in a hot well-seasoned ridged grill pan over moderate heat.)

Spoon tamarind sauce over shrimp (still in shells) in a serving dish.