Cut the chicken into bite-sized pieces and set aside.
In a bowl, mix cornstarch and flour.
Dip each chicken piece in the flour mixture, then into the beaten egg.
Heat sesame oil in a pan over medium heat.
Fry the chicken pieces until golden and crispy, about 5-7 minutes.
Remove the chicken and drain on paper towels.
In the same pan, combine orange juice, soy sauce, sugar, rice vinegar, garlic, and ginger.
Bring the sauce to a simmer, stirring occasionally.
Add the fried chicken back into the sauce, coating well.
Cook for another 2 minutes to thicken the sauce.