
Bring a large pot of water to a boil. Cook noodles according to package directions. Once done, transfer the noodles to a colander to drain, then rinse with cold tap water to stop cooking. Drain and set aside.
Bring the same pot of water back to a boil and add chicken tenderloins. Keep the water at a very low simmer that barely bubbles. Cook the chicken for 5 to 7 minutes, until just cooked through. Transfer to a plate to cool. Then shred the chicken using two forks.
Mix the chili crisp, soy sauce, Chinkiang vinegar, sesame paste, sesame oil, sugar, ginger, and Sichuan peppercorn together in a medium bowl.
In a large bowl, combine the cooked noodles (*Footnote 2), red onion, chicken, cucumber and most of the noodle sauce, reserving 1 to 2 tablespoons. Toss to coat well. Transfer to each individual serving bowl, top with peanuts and cilantro, if using. (*Footnote 3) Taste the noodles and mix in the remaining sauce if needed. Serve at room temperature with the remaining sauce.