MAKES 20 SKEWERS
2 tbsp. tamarind paste
1 1/2 cups coconut milk
2/3 cup fresh grated coconut
1/2 cup Thai red curry paste
1/2 cup minced lemongrass
1/3 cup dark brown sugar
1/3 cup thinly sliced shallots
2 tbsp. fish sauce
3 Kaffir lime leaves, stemmed, minced
1 pandan leaf, tied into a knot
2 lb. (about 60) large mussels
Stir together tamarind and 5 tbsp. boiling water in a bowl until dissolved; pour through strainer into a 2-qt. saucepan. Add coconut milk, coconut, curry paste, lemongrass, sugar, shallots, fish sauce, lime leaves, pandan, and 3 tbsp. water; heat over medium-high heat. Cook, stirring, until thickened, about 10 minutes. T-ransfer to a bowl and set aside.
Bring 1 cup water to a boil in a 6-qt. saucepan over medium-high heat. Add mussels, cover, and cook until all mussels open, about 4 minutes. Remove from heat; let cool. Remove meat from shells and stir into marinade; chill 2 hours.
Build a hot charcoal fire in a grill. Thread 3 mussels each on 20 skewers; grill, turning, until charred, about 6 minutes.