Marinate chicken cubes with 1/4 cup soy sauce, 2 tbsp orange juice, 1/4 cup cornstarch for 4 – 5 hours.
Heat oil in a pan and cook the chicken for a couple of minutes.
Add 3/4 cup orange juice, 1 tbsp soy sauce, vinegar, brown sugar, and 1 tbsp cornstarch to the chicken and cook until tender.
Serve Orange Chicken hot.