In a bowl, whisk the egg white until frothy. In a separate bowl, combine flour, corn starch, salt, and pepper. Dip each chicken piece into the egg white, then coat with the flour mixture.
Heat oil in a pan over medium-high heat. Fry the chicken until golden brown and cooked through. Place on a paper towel-lined plate to drain excess oil.
In a saucepan, combine vinegar, soy sauce, minced garlic, crushed red pepper flakes, sesame seeds (optional), orange juice, ginger, and orange or lemon zest. Add honey to the mixture and bring to a simmer.
In a small bowl, mix starch with water to create a slurry. Slowly pour the slurry into the simmering sauce, stirring constantly until the sauce thickens.
Toss the fried chicken pieces into the thickened orange sauce, ensuring they are evenly coated.
Sprinkle sesame seeds (optional) over the coated chicken for an extra touch. Serve your homemade Orange Chicken over steamed rice or noodles.