
Make the peanut sauce. In a small bowl, combine the peanut butter, hoisin sauce, white vinegar, milk, minced garlic, and chili paste. Stir, then microwave for 30 seconds and mix again until smooth. Let it cool, then adjust with a little extra milk or water if needed.
Soak the vermicelli noodles in warm water for about 2 minutes, or according to the package directions, until just tender. Drain well and set aside.
Prepare the shrimp by peeling, deveining, and slicing each one in half lengthwise so they lie flat inside the rolls.
Trim the thick core from the lettuce leaves so they are easier to roll. Set out the lettuce, bean sprouts, mint leaves, noodles, and shrimp for assembly.
Make the filling bundles by placing a small amount of vermicelli and bean sprouts inside each lettuce leaf. Roll each leaf up snugly and place seam-side down.
Fill a large bowl with warm water. Dip 1 rice paper sheet, or 2 sheets stacked together for extra strength, into the water for about 2 seconds until just pliable.
Lay the softened rice paper on a clean board or work surface. Position it so the smoother side will face outward once rolled.
Near the top third of the rice paper, arrange 3 shrimp halves with a mint leaf between them for a neat presentation.
Place 1 lettuce bundle in the center of the rice paper, below the shrimp.
Fold the left and right sides inward over the filling. Starting from the bottom, roll upward firmly but gently until sealed. The rice paper will stick to itself.
Repeat with the remaining ingredients, keeping finished rolls covered lightly with a damp towel so they do not dry out.
Serve the spring rolls right away with the peanut dipping sauce on the side.