• Gather all the ingredients.
  

To Make the Dipping Sauce

• For the sauce, grind 2 Tbsp toasted white sesame seeds in your mortar and pestle. Transfer the ground sesame seeds into a small bowl. Then grate ½ inch ginger and 1–2 cloves garlic (I used a Microplane grater).
  
• In a small bowl, whisk together 3 Tbsp sugar, 3 Tbsp soy sauce, 2 Tbsp rice vinegar (unseasoned), 2 tsp toasted sesame oil, and 1 tsp la-yu (Japanese chili oil). Set aside.
  

To Prepare the Ingredients

• Chop 2 green onions/scallions into 3 pieces each. Cut 1 knob ginger into thin slices.
  
• Butterfly ½ lb boneless, skinless chicken breast. Butterflying is a really useful technique to create a uniform thickness throughout a piece of meat so that it will cook more quickly and evenly. First, remove the tender (small inner fillet) by cutting away any connective tissue. Turn the breast over and with the edge of a knife parallel to the cutting board, cut the length of the side of the breast. Carefully slice the breast in half widthwise almost to the other edge. Keep the edge intact and open the breast along the fold.
  
• In a large pot, add 4 cups water, 1 tsp Diamond Crystal kosher salt and 2 Tbsp sake. Put the sliced ginger and scallions in the pot and bring it to a boil. Once boiling, add the chicken breast and tender to the pot, reduce the heat to the lowest setting, and cover with the lid. Cook the chicken for 15 minutes.
  
• Meanwhile, julienne 1 carrot and 2 Japanese or Persian cucumbers. I use a julienne slicer but if you don’t have one, cut into thin sheets first and then cut into matchstick-size strips.
  
• Remove the chicken from the pot onto a plate and immediately cover with plastic wrap to prevent it from drying out. Once the chicken has cooled, shred the chicken into small pices with your hands.
  
• Rinse 5 butter lettuce leaves, 2 sprigs mint leaves, and 1 bunch cilantro (coriander) under running water and dry completely. Set all the ingredients on a work surface.
  

To Assemble the Spring Rolls

• Pour hot water in a large bowl. Work with 1 wrapper (of the 10 rice paper wrappers) at a time. First, soak 1 wrapper in the hot water and rotate 2–3 times, about 10 seconds. The wrapper will still feel slightly stiff but don’t worry, it will become softer. Place it flat on the work surface.
  
• Lay the butter lettuce, chicken, carrot, and cucumber at the bottom third of the wrapper closest to you. Then, place the mint and cilantro leaves at the top third of the wrapper.
  
• Pressing firmly down to hold the filling in place, fold up the bottom of the wrapper and start rolling tightly.
  
• Around the middle of the wrapper, fold both sides of the wrapper in and roll up tightly to the top. Place on a plate and cover loosely with plastic wrap and repeat with the remaining wrappers and fillings. Cut in half or thirds. Serve with the Sesame Dipping Sauce.
  

To Store

• Keep the spring rolls tightly covered with plastic wrap at room temperature for up to 2 hours.