In a mixing bowl, combine the beaten egg, 1 tablespoon of soy sauce, and 1 tablespoon of sesame oil. Mix well.

Add the chicken pieces, ensuring they are well-coated. Let it marinate for at least 30 minutes.

In another bowl, mix the all-purpose flour and cornstarch.

Remove the chicken from the marinade, and toss the pieces in the flour mixture until fully coated.

Heat vegetable oil in a deep skillet or saucepan over medium-high heat. It should be hot enough to sizzle when you drop a piece of chicken in.

Carefully add the coated chicken pieces to the hot oil in batches, frying until golden brown and cooked through (approximately 5-7 minutes).

Once done, transfer the chicken to a paper towel-lined plate to drain excess oil.

In a separate saucepan, combine the orange juice, orange zest, sugar, rice vinegar, 2 tablespoons of soy sauce, minced garlic, and minced ginger.

Bring this mixture to a boil over medium heat, then reduce to simmer for about 5 minutes.

Stir in the cornstarch-water mixture to thicken the sauce and continue cooking until it reaches your desired consistency.

Toss the fried chicken in the orange sauce, ensuring it’s well-coated, and let it cook for an additional minute.

Serve hot, garnished with sliced green onions and sesame seeds if desired.