Bring a pot of salted water to a boil. Add the noodles and cook according to package directions. Drain and rinse under cold water.
In a large bowl whisk together the sesame oil, lime juice, and fish sauce. Add the noodles, chicken, cabbage, carrots, and snap peas; toss to combine. Sprinkle with peanuts, if desired, and serve with lime wedges
Season 3/4 lb skinless boneless chicken thighs (3 thighs) with salt and pepper. Grill or broil until no longer pink (170°F), about 15 minutes. Refrigerate until needed.