How to Make It
Using a fork or your fingers, shred the chicken meat, discarding the skin and bones.
In a large bowl, combine the chicken, carrots, scallions, tarragon, ½ teaspoon salt, and ¼ teaspoon pepper.
In a small bowl, whisk together the oil, vinegar, mustard, and ¼ teaspoon each salt and pepper.
Divide the radicchio leaves among plates, top with the chicken mixture, and drizzle with the vinaigrette.