Easy Kung Pao Chicken

boneless, skinless chicken breasts, cut into bite-sized pieces

low-sodium soy sauce, divided

cornstarch

or 3 dried red chilies

cooking oil (I used canola)

garlic, finely minced

red bell pepper, cut into 1-inch dice

medium zucchini, chopped (my addition)

fat-free vegetable or chicken broth

Chinese black vinegar or non-aged balsamic vinegar (I used reg. balsamic)

chopped, unsalted roasted peanuts