Slice boneless, skinless chicken into thin, even pieces
Pat the chicken dry with paper towels
Season lightly with salt and pepper
Toss with a small amount of cornstarch if desired
Heat a wok or skillet over medium-high to high heat
Add a small amount of oil with a high smoke point
Add the chicken in a single layer
Let it cook undisturbed for a short time
Stir-fry until the pieces are browned and cooked through
Remove the chicken from the pan before cooking vegetables if needed
Return the chicken to the pan near the end of cooking with the sauce
Cook until the chicken reaches 165°F internally