Southeast Asian Shrimp with Bibb Lettuce and Herbs

Shell and devein shrimp. In a 3-quart saucepan of boiling water cook shrimp 3 minutes, or until just cooked through, and drain in a colander. Cool shrimp slightly. In a large baking dish chill shrimp in one layer, loosely covered with plastic wrap. (Shrimp may be cooked 1 day ahead and chilled, covered.)Mince garlic. Wearing rubber gloves, seed 2 chilies and mince all 3 chilies. In a bowl stir together garlic, chilies, lime juice, fish sauce, brown sugar, and water until sugar is dissolved. (Dipping sauce may be made 2 days ahead and chilled, covered.)Just before serving, assemble hors d'oeuvres: On each lettuce leaf arrange 1 shrimp, 1 mint leaf, and 1 coriander sprig. Serve shrimp with dipping sauce.