Cook noodles as directed. Boil shrimp for 5 minutes, shell, devein and cut in half. Boil pork for 20 minutes in water to cover then remove and slice thinly. Remove cilantro from its stem and keep whole. Blanch the scallions in boiling water for 1 minute and cut into 3 equal sections. Cut each lettuce leaf in half. Place on the narrow end of the lettuce, 1 slice pork, 1 piece shrimp, 1 tablespoon of noodles, 2 mint leaves and 2 pieces of cilantro. Roll into a cylinder. Tie a scallion around the center of the cylinder and serve.