Ingredients

• 1/2 cup tamarind pulp (from a pliable block)
• 1 cup boiling-hot water
• 3 tablespoons plus 1 teaspoon packed palm or dark brown sugar
• 2 tablespoons soy sauce
• 2 tablespoons Asian fish sauce
• 1 tablespoon fresh lime juice
• 10 (1- to 1 1/2-inch-thick) pieces mahimahi fillet with skin (6 oz each)
• 2 tablespoons vegetable oil
• 1 teaspoon kosher salt

Instructions

1. Soak tamarind pulp in boiling-hot water in a small bowl, stirring occasionally, until softened, about 5 minutes. Pour mixture into a medium-mesh sieve set into a bowl, then force pulp through sieve, discarding seeds and fibers. Add brown sugar, soy sauce, fish sauce, and lime juice, stirring until sugar is dissolved.
2. Prepare grill for cooking over medium-hot charcoal (moderate heat for gas).
3. Brush fish all over with oil, then sprinkle with salt. Grill, skin sides down, on lightly oiled grill rack, covered only if using gas grill, until skin is crisp, about 4 minutes. Turn fish over and grill until just cooked through, about 6 minutes more. Brush tamarind sauce all over fish and grill 1 minute.
4. Serve with remaining sauce.