Cook the noodles according to the package directions. Drain them and rinse with cold water to stop the cooking, then let cool completely.
Step 2
In a small bowl, whisk together lime juice, fish sauce, sugar, peanut butter, garlic, and chilies to make the dressing. Gradually whisk in the vegetable oil until fully combined and emulsified. Stir in cilantro and mint.
Step 3
In a large bowl, mix the cooled noodles with chicken, cucumber, cabbage, and bell peppers. Pour in the dressing and toss everything together until well coated.
Step 4
Serve chilled and garnish with scallions and peanuts before serving.