Shanghai Chicken Salad

1/2 cup rice vinegar
1/2 cup reduced-sodium soy sauce
1/3 cup hoisin sauce
1 1/2 tablespoons grated fresh ginger root
1/4 cup toasted sesame oil
18 ounces chicken breasts, trimmed 
1/2 head Napa cabbage, shredded
1 large red bell pepper, seeded and sliced
9 scallions, sliced thin on the diagonal
1 cup chow mein noodles

Whisk vinegar, 3 tablespoons soy sauce, hoisin sauce, ginger and sesame oil together in a medium bowl. Place chicken in single layer in Dutch oven. Pour 1/2 cup vinegar mixture over chicken breasts; reserve remaining vinegar mixture to use as dressing. Add remaining 1/3 cup soy sauce and 3 cups water to pot. Bring to boil over high heat. Cover, reduce heat to low, and simmer chicken until cooked through, 7 to 10 minutes.

Transfer chicken to plate, cover loosely with plastic wrap, and refrigerate until cool enough to handle. Shred chicken into long thin strands using two forks or fingers.

Transfer chicken to large serving bowl, toss with 2 tablespoon dressing, and season with salt and pepper. Add cabbage, bell pepper, scallions, and remaining dressing and toss to combine. Sprinkle with chow mein noodles and serve.