How to Make It
Cut each chicken breast into five diagonal strips. In a medium saucepan, combine the broth, 1/4 of the scallions, and 1/4 teaspoon of the salt. Bring to a simmer, add the chicken, stir, and cover the pan. Cook over low heat for 5 minutes. Turn the heat off and let the chicken steam for 5 minutes. Remove the chicken from the pan and shred it.
In a large bowl, combine the shredded chicken, the remaining scallions, the cabbage, carrots, and 4 tablespoons of the herbs, if using. In a small glass or stainless-steel bowl, whisk together the lime juice, soy sauce, sugar, red-pepper flakes, and the remaining 1/4 teaspoon salt. Toss the salad with the dressing. Sprinkle with the remaining 2 tablespoons chopped herbs and the peanuts.
Asian fish sauce is available at Asian markets and some supermarkets.