Whisk peanut butter, soy sauce, honey, lime juice, and sriracha, adding warm water as needed to make a smooth sauce.
Pour sauce into the skillet with chicken, simmer for 1-2 minutes, stirring to emulsify.
Add cooked noodles to the skillet, toss to coat and heat through for 1-2 minutes. Stir in green onions and cilantro, finish with sesame oil and black pepper.
Notes
Adjust spice level with more or less sriracha, and add extra lime or salt to taste before serving.