Preparation

Prepare the filling ingredients:

• Bring a 3- to 4-quart saucepan of water to a boil over high heat. Meanwhile, soak the noodles in a bowl of cold water until pliable, about 7 minutes. Drain and boil, stirring once or twice, until tender, about 15 seconds. Transfer with tongs to a colander and immediately rinse under cold running water until cool. Drain and transfer to a bowl; cover with plastic wrap until ready to use.
• Add the pork and vinegar to the boiling water, lower the heat to maintain a simmer, and cook until an instant-read thermometer inserted into the center registers 140°F, about 8 minutes. Transfer with tongs to a cutting board, let cool to room temperature, and then cut crosswise into 24 very thin slices.
• In the same water, cook the shrimp just until pink and opaque, about 2 minutes. Drain in a colander and rinse under cold running water until cool. Halve each shrimp lengthwise.

Assemble the rolls:

• Arrange the noodles, pork, shrimp, mint, lettuce, cucumber, carrot, and rice paper wrappers around a work surface. Have a platter nearby for the finished rolls, and a small bowl of water for wetting your fingers.
• Fill a large, shallow, round dish with cold water. Submerge a rice paper wrapper in the water until very pliable, about 1 minute.
• Carefully remove the wrapper from the water, gently shaking off excess water. Lay it flat on the work surface and blot dry with a clean kitchen towel.
• On the lower third of the wrapper, leaving about 1 inch of space along the side and bottom edges, layer the fillings in the following order: 3 shrimp halves, cut side up; 2 mint leaves, lengthwise; 1 lettuce leaf half, folded or trimmed to fit if necessary; 2 pork slices; 5 or 6 cucumber slices; about 2 Tbs. of the noodles; and about 6 carrot strips.
• Wet your fingers to keep the wrapper from sticking to them. Starting with the edge closest to you, fold the wrapper up and over the fillings. Be sure the fillings are snugly compressed but not so tight that the wrapper is strained, or it may rip.
• Once the first turn is tight, fold the right and left sides of the wrapper in, closing off the ends as though making an envelope.
• Continue rolling the wrapper tightly all the way to the top and press the seam closed. Set the roll seam side down on the platter. Repeat with the remaining wrappers and fillings. Don’t let the finished rolls touch one another or they’ll stick.

Serve the rolls:

• Cut the rolls in half on the diagonal, if you like, and serve with your choice of dipping sauces.

Make Ahead Tips

You can prepare and refrigerate the fillings a couple of hours ahead and assemble the rolls about an hour before serving. Keep them at room temperature, with slightly damp paper towels under and over the rolls and cover with plastic to keep them moist.