Prepare the filling: Slice the cooked shrimp in half lengthwise. Thinly slice the cooked pork. Julienne the carrot and cucumber. Cook the vermicelli noodles according to package instructions and drain.

Make the dipping sauce: In a small bowl, mix fish sauce, lime juice, sugar, minced garlic, and chopped chili (if using). Stir until the sugar dissolves and set aside.

Soak the rice paper: Fill a large shallow dish with warm water. Dip one rice paper wrapper into the water for about 5-10 seconds until it softens. Place it on a clean, damp kitchen towel.

Assemble the spring roll: On the lower third of the rice paper, layer a few shrimp halves (cut side up), pork slices, vermicelli noodles, carrot, cucumber, lettuce, and herbs (mint, cilantro, Thai basil).

Roll tightly: Fold the sides of the rice paper over the filling, then roll from the bottom up, keeping it tight to prevent air pockets.

Repeat: Continue with the remaining ingredients. Serve immediately with the prepared dipping sauce.

Storage tip: If not serving immediately, cover the spring rolls with a damp cloth to prevent them from drying out.