Stir egg, salt, and 1 tablespoon oil and mix well. Stir cornstarch and flour together. Add chicken pieces, stirring to coat.
Heat oil for deep frying. Add chicken. Cook in small batches for 3-4 minutes. Do not over cook.
Remove chicken and drain on paper towels. Set aside.
Mix orange sauce ingredients together.
In a clean skillet add 1 tablespoon of oil,Stir fry for 10 seconds. Add green onion and rice wine vinegar and stir for about 5 seconds. Add orange sauce and bring to a boil. Add cooked chicken and stir until coated.