Heat the pork in a large nonstick skillet over high heat. Season with the salt and pepper. Cook until the meat is no longer pink, about 5 minutes, stirring frequently. Transfer pork to a paper towel-lined plate using a slotted spoon. Let cool. Mix the hoisin sauce and water chestnuts together in a small bowl. Add the pork and mix well. Refrigerate while preparing the rice papers. ASSEMBLY: Fill a pie plate or other wide, shallow container with lukewarm water(do not use cold water or hot water). Place 2 rice papers in the water. Let sit until somewhat soft, about 45 seconds. Remove 1 paper at a time and place on a paper towel. Cover with an additional paper towel. Repeat the process until there are 12 layers of rice paper. The rice paper will become pliable 1 to 2 minutes after being stacked. Invert the stack and use the rice papers in the order in which they were removed from the water. Place 3 rice papers at a time on a clean work surface. Sprinkle each rice paper with 1/8 teaspoon of the sesame seeds. Place 1 basil leaf on the bottom third of each rice paper. Top with 1 tablespoon of the pork mixture. Cover with one mint leaf. Fold the right and left edges toward the center of the filling, pressing firmly. Fold the bottom edge of the rice paper toward the center and gently but firmly roll until the top edge is reached and a rectangle 11/2 by 2 inches is formed. Repeat until the first 12 rice paper rolls are complete. Cover assembled wraps with a very damp towel and cover with plastic wrap. Soak remaining rice paper wraps and assemble until remaining ingredients have been used. Cover the wraps as directed. These rolls can be left at room temperature for up to 3 hours. Do not refrigerate or the rice paper will harden.