Combine cornstarch, salt, pepper, and garlic powder in a large bowl.
Chop chicken into bite-sized pieces and toss them in the cornstarch mixture.
Place the oil in a skillet on your stovetop and allow the oil to become hot. Add the chunks of chicken to the oil in a single layer, careful not to overcrowd it. You may need to cook the chicken in two batches, depending on the size of your skillet.
Once the chicken reaches an internal temperature of 165F, remove it from the skillet and allow it to rest on a plate.
In the same skillet, add chopped bell peppers, onion, Szechuan peppercorns, and red chilies and cook over medium-low heat until the peppers are tender and the onions are translucent.
While the vegetables are cooking, mix together the chicken broth, soy sauce, sesame oil, hoisin sauce, cornstarch, and brown sugar in a separate bowl.
Add the sauce mixture to the cooked vegetables. Allow it to simmer until the sauce begins to thicken. Next, stir the cooked chicken into the sauce and veggie combination.
Remove the Szechuan Chicken from the skillet, serve and enjoy!