Cut chicken into 1-inch cubes.
In a bowl, whisk flour, cornstarch, salt, pepper, egg, oil, and water until smooth.
Add chicken to the batter, ensuring each piece is well coated. Chill for 10–30 minutes.
Heat oil to 350°F (177°C) in a deep pan.
Fry chicken in batches for 2–3 minutes until golden and crispy. Remove and set aside.
In a saucepan, combine orange juice, zest, soy sauce, vinegar, brown sugar, and garlic. Bring to a gentle boil.
Add cornstarch slurry and stir until the sauce thickens.
Toss fried chicken in the sauce until fully coated. This Orange Chicken Recipe creates a rich, glossy finish.
Garnish with sesame seeds, green onions, and red pepper flakes. Serve immediately.