In a pot, bring water to a rolling boil. Add the shrimp and cook for about 1 minute until pink and opaque. Remove and chill in ice water.

In a bowl, whisk rice vinegar, sugar, fish sauce, and lime juice until sugar dissolves. Add julienned cucumber, carrot, radishes, and scallions. Toss gently.

In the same boiling water, soak cellophane noodles for about 10 minutes until tender. Drain, drizzle with sesame oil, and set aside.

Fill a shallow dish with water. Dip a rice paper wrapper for about 30 seconds until pliable. Lay flat on a damp surface.

Place a lettuce leaf on the wrapper, layer with shrimp, vegetables, and noodles. Fold edges and roll tightly.

Serve assembled rolls with dipping sauce like nước chấm or a spicy variation.