1, To poach the shrimp, fill a small saucepan half full with water, add the salt, and bring to a rolling boil over high heat. Add the shrimp, remove from the heat, and let stand for 3 to 5 minutes, or until the shrimp have curled nicely and are pinkish orange. Lift them out with a slotted spoon and set aside to cool. Leave the water in the pan.
2, While the shrimp are poaching, trim any excess fat from the pork chop. Return the water in the pan to a rolling boil and drop in the pork. When the water starts bubbling at the edges of the pan, remove the pan from the heat and cover tightly. Let stand for 20 minutes. The pork should be firm yet still yield a bit to the touch. Remove the pork from the pan and let cool. Save the light stock for another use or discard.
3, Working with 1 shrimp at a time, lay it flat on a cutting board and cut in half horizontally. (Use the index and middle fingers of your noncutting hand to keep the shrimp in place as you wield the knife.) Devein the shrimp as necessary. Set aside on a plate.
4, Thinly slice the pork across the grain into strips about ⅛ inch thick, ½ inch wide, and 4 inches long. Add to the plate of shrimp.
5, Set up a wrapping station composed of a flat work surface (a cutting board, inverted baking sheet, or dish towel) and a bowl of water for dipping the rice papers. Place the shrimp, pork, noodles, lettuce, and herbs nearby.
6, Dip a rice paper round in water and then place it on your work surface. ( See tips on working with rice paper .) When the rice paper is pliable and tacky, fold a lettuce leaf in half along its central spine and then tear off the spine. Place the folded leaf on the lower third of the rice paper round. Put about ¼ cup of the noodles on top of the lettuce, spreading them in a rectangle. Lay a couple of pork strips on top (slightly overlapping, if necessary), and then arrange a few mint and cilantro leaves on top of the pork, spreading them out to distribute their flavors evenly.
Bring up the lower edge of the rice paper to just cover the herbs. Then roll the rice paper a half turn so that the lettuce is on top and visible through the rice paper. Add 3 shrimp halves, cut side up, to the unrolled portion of rice paper, lining them up snugly along the partially finished roll. Fold the sides of the round inward to cover the filling. Roll one more full turn, so that the orange sides of the shrimp are now facing up and visible through the rice paper. Tuck 2 or 3 Chinese chives into the roll, letting them extend out one end. Continue to roll until you have a snug cylindrical package. The rice paper is self-sealing. Use a knife or scissors to trim the chives, leaving a ¾-inch “tail” extending from the end.
7, Repeat this process to make 16 rolls in all, placing the finished rolls on a serving platter. If the rolls seem too long to manage and eat comfortably, cut them in half on the diagonal. Serve the rolls with the sauce. Diners can dip the rolls into the sauce or spoon some sauce onto the rolls.
While the pork and shrimp may be poached a day ahead, slice them on the day you wrap. The noodles may be cooked early in the day, covered with plastic wrap, and kept at room temperature. You may wrap the rolls 2 hours in advance of serving. Keep them covered with plastic wrap to prevent the rice paper from drying out and becoming unpleasantly tough. If you are cutting the rolls, do so just before serving, or they may lose their nice shape.
You can wrap other items in these rolls, too, but they must be thinly sliced so that they are flexible enough to roll. Seeded cucumber strips, julienned carrot, seared tofu strips, and slices of leftover grilled meats are among the possibilities. Different fresh herbs, such as Vietnamese coriander (rau răm) or Thai basil, may be incorporated to introduce different flavors. The elements that you need to preserve are the lettuce leaves and noodles, which give the rolls body, and the hoisin-garlic sauce, which marries all the flavors.
Southern Vietnamese Salad Spring Rolls (Gỏi Cuốn) is adapted from the book "Into the Vietnamese Kitchen" by Andrea Nguyen. Copyright © 2006 by Andrea Nguyen.