Combine the lightly beaten egg with cornstarch in a bowl.
Add the cubed chicken thighs and coat thoroughly.
Let the chicken stand for 10 to 15 minutes.
In a separate bowl, mix together the light soy sauce, sake or dry sherry, frozen orange juice concentrate, spicy brown bean sauce, minced ginger, sesame oil, and cornstarch until smooth.
Prepare the orange peel by removing as much of the white pith as possible and flattening the peel.
Heat cooking oil in a wok until hot.
Dust each piece of chicken with cornstarch, shake off excess, and fry in the hot oil until lightly browned and crispy.
Remove the chicken and drain on paper towels.
Carefully drain the oil from the wok and return it to the heat.
Add fresh oil, then stir-fry the orange peel, dried red chili peppers, and minced garlic until fragrant.
Pour the prepared sauce into the wok and cook, stirring constantly, until thickened and glossy.
Add the fried chicken back to the wok and toss briefly to coat evenly.
Serve immediately over hot steamed rice.