Grilled Tamarind-Marinated Prawns

Prep - In a medium heat-proof bowl, add tamarind pulp and 2 1/4 cups hot water. Let stand for 10 minutes. Using a metal spoon, mash tamarind pulp so meat is released from the fibers and seeds. Strain tamarind pulp through fine mesh sieve into another medium bowl. You should get approximately 1 1/2 cups tamarind juice.

Prep the Shrimp - Using a sharp knife or kitchen shears, butterfly each prawn or shrimp by cutting along the back, going about halfway through the flesh. Leave the shell, head, and tail intact, and keep the two halves connected without flattening the meat. Remove vein and discard.

Brining - In a large bowl, combine 4 cups (960 ml) ice water, 1 tablespoon salt, and baking soda. Mix well. Add deveined prawns or shrimp and soak for 15 minutes. Remove prawns and pat them dry with paper towels.

Marinating - In a large bowl, whisk 1 1/4 cups prepared tamarind juice, 1/4 cup and 2 tablespoons sugar, 1/4 cup and 2 tablespoons fish sauce, shallot, 2 tablespoons garlic, 1 teaspoon salt, and pepper until sugar dissolves. Add prawns to marinade and refrigerate for 4 to 6 hours, flipping them halfway through.

Dipping Sauce - In a small saucepan, combine 1/4 cup tamarind juice, remaining 1/4 cup fish sauce, remaining 2 tablespoons sugar, remaining 2 tablespoons garlic, and bird's eye chile and bring to a boil over medium-high heat. Turn heat down to medium-low and simmer, stirring often, until sauce is slightly reduced, about 10 minutes.

Grilling - For a Charcoal Grill: Light one chimney full of charcoal. When all charcoal is lit and top is covered with gray ash, pour out and arrange coals on half of charcoal grate. Set cooking grate in place, cover grill, and allow to preheat for 5 minutes. For a Gas Grill: Turn all burners to high; cover; and heat grill until hot, about 15 minutes. Leave all burners on high.

Grilling - Clean and oil grilling grate. Shake off excess marinade and place half of prawns or shrimp directly over hot side of grill. Cook, flipping halfway through, until prawns or shrimp are just cooked through and meat is no longer opaque, 2 to 3 minutes per side. Transfer to large platter and repeat with remaining prawns or shrimp.

Serving - Garnish prawns with a few sprigs of cilantro, and serve immediately with tamarind dipping sauce.