Place chicken pieces in a large bowl and add 3 tablespoons corn starch, salt and pepper. Stir to coat.
Heat a large pan over high heat and add oil (add more oil if needed to coat the bottom of your pan).
Meanwhile, make the Orange Chicken sauce. Whisk together the marmalade, juice, soy sauce, vinegar, garlic, ginger, pepper flakes, chicken broth and 2 tablespoons corn starch.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)