1. Cut the chicken into small cubes. Crack the eggs into a bowl. Whisk them well. Add the chicken cubes and set aside for 10 minutes.
In a bowl, mix the flour, cornstarch, and salt. Drain the chicken pieces and dredge them little by little in the flour mixture. Stir so the flour coats everything. Shake off the excess flour and place them on a plate.
Pour sunflower oil into a small deep frying pan and when hot, fry the chicken over high heat for about 3 minutes or until golden brown. Remove the chicken onto a plate lined with kitchen paper.
Prepare the orange sauce: In a pan, combine the orange juice, sugar, rice vinegar, soy sauce, sesame oil, garlic, ginger, and chili flakes. Turn on the heat, and once the ingredients are warm, reduce the heat and simmer for 3 minutes.
Dissolve the cornstarch in the water and pour it into the sauce. Stir and add the orange zest. Simmer for another 2 minutes or until the sauce thickens.
Add the chicken and stir well to coat everything with the sauce. Serve sprinkled with sesame seeds and spring onions. If you like, serve the chicken with boiled basmati rice.