Bring a pot of water to boil. Add shrimp and cook for 2-3 minutes until pink and opaque. Remove, cool in ice water, then peel and devein. Slice each shrimp in half lengthwise.

Cook rice vermicelli according to package directions, usually 3-4 minutes in boiling water. Drain and rinse with cold water. Set aside.

Prepare all vegetables: wash and dry lettuce leaves, julienne cucumber into thin matchsticks, and pick cilantro and mint leaves from stems. Arrange all ingredients on a large platter for easy assembly.

For the peanut sauce, combine peanut oil, garlic, hoisin sauce, and water in a small saucepan. Heat gently while stirring. Add crushed peanuts and stir until smooth. Remove from heat and let cool.

Fill a large shallow dish with warm water. Dip one rice paper wrapper for 3-5 seconds until just softened (do not oversoak). Lay on a clean, damp kitchen towel.

On the lower third of the wrapper, place 2 lettuce leaves, a small handful of vermicelli, 3-4 cucumber sticks, several cilantro and mint leaves, and 3 shrimp halves.

Fold the bottom edge over the filling, fold in both sides tightly, then roll up firmly to create a neat cylinder. The shrimp should be visible through the wrapper. Place seam-side down on a platter.

Repeat with remaining wrappers and filling. Keep finished rolls covered with a damp towel to prevent drying.

Serve immediately with peanut dipping sauce on the side. Rolls are best enjoyed within 1-2 hours of making.