In a large bowl, combine flour, salt, and pepper. Dredge the chicken pieces in the flour mixture, shaking off any excess.
Dip the floured chicken into the beaten eggs, then coat with panko breadcrumbs, pressing gently to adhere.
In a large skillet or deep fryer, heat about 2 inches of vegetable oil over medium-high heat until it reaches 350°F.
Fry the chicken in batches for about 4-5 minutes or until golden brown and cooked through. Remove and drain on paper towels.
In a saucepan over medium heat, combine orange juice, sugar, soy sauce, rice vinegar, cornstarch, ginger, garlic, and sesame oil. Stir until the mixture thickens and bubbles, about 5-7 minutes.
Toss the fried chicken in the orange sauce until well coated.
Serve the orange chicken hot, garnished with sliced green onions and sesame seeds.