Marinate the chicken pieces with salt and pepper for 15-30 minutes.
Prepare the breading by mixing flour, salt, and pepper in one bowl, and beating eggs in another bowl.
Dredge marinated chicken in flour, dip in eggs, and coat with panko breadcrumbs.
Heat vegetable oil in a skillet over medium-high heat and fry chicken pieces for 4-5 minutes on each side until golden brown.
Prepare the orange sauce by combining orange juice, sugar, soy sauce, rice vinegar, cornstarch, garlic, and ginger in a saucepan and cook until thickened.
Toss the fried chicken pieces with the orange sauce until well coated and serve immediately garnished with green onions and sesame seeds.