Prepare the chicken: In a bowl, whisk egg with salt and pepper. Add chicken pieces and toss to coat.
Coat the chicken: Mix cornstarch and flour together. Dredge chicken pieces until fully coated.
Fry the chicken: Heat oil to 350°F (175°C). Fry chicken in batches for 4–5 minutes until golden and crispy. Drain on paper towels.
Make the sauce: In a saucepan, whisk soy sauce, honey, vinegar, ketchup, sesame oil, cornstarch, water, garlic, and ginger.Cook over medium heat until thick and glossy (3–4 minutes).
Combine: Add fried chicken to the sauce and toss until evenly coated.
Garnish & serve: Sprinkle with sesame seeds and green onions. Serve hot.