In a large bowl, combine the shredded chicken, cabbage, carrots, red bell pepper, cilantro, mint, green onions, and roasted peanuts. Toss gently to mix all the ingredients evenly.
In a separate small bowl, whisk together the fish sauce, lime juice, sugar, sesame oil, minced garlic, and red pepper flakes until the sugar is dissolved.
Pour the dressing over the salad mixture and toss well to coat all the ingredients.
Let the salad sit for about 10-15 minutes to allow the flavors to meld.
Serve chilled or at room temperature.