Prepare the Noodles: Bring a pot of water to a boil. Add the rice vermicelli noodles and cook according to package directions until just tender but still firm (al dente). Drain the noodles and rinse under cold water to stop cooking. Return them to the pot and toss with the toasted sesame oil and sea salt. Set aside.
Prep Your Vegetables and Herbs: Wash and dry all vegetables thoroughly. Tear the butter lettuce into bite-sized pieces, slice the red cabbage thinly, peel and julienne the carrots, and slice the cucumbers and jalapeños into thin strips. In a small bowl, combine the green onions, cilantro, and mint. Set all fillings within easy reach for assembly.
Soften the Rice Paper: Fill a shallow, wide pan (such as a 9-inch cake pan or pie dish) with about an inch of warm water. Dip one rice paper wrapper into the water and let it sit for roughly 20 seconds, until pliable but not overly soft. Remove it carefully and lay it flat on a clean, lint-free tea towel.
Assemble the Spring Rolls: Place a few pieces of butter lettuce along the lower third of the softened rice paper, leaving about an inch border around the edges. Add a small handful of noodles, followed by some red cabbage, carrot strips, cucumber, jalapeño slices, and a generous sprinkle of the herb mix. Fold the bottom edge of the rice paper up over the fillings, then fold in the sides like a burrito, and roll tightly from bottom to top to enclose the ingredients fully.
Prepare the Peanut Sauce: In a small bowl, whisk together the peanut butter, rice vinegar, tamari, honey, sesame oil, and minced garlic. Add water one tablespoon at a time until the sauce reaches a creamy, dip-friendly consistency.
Serve: Plate the spring rolls whole or cut them diagonally with a sharp knife. Serve with the peanut dipping sauce on the side.
