Combine the marinade ingredients in a large bowl. Stir.
Add the chicken. Marinate for 1 hour.
Meanwhile, combine the sauce ingredients in a bowl. Mix well and then set aside.
Heat the oil in a cooking pot.
Dredge the marinated chicken in cornstarch and then dip into the beaten egg mixture.
Roll the chicken back in the cornstarch and then deep fry until the color turns light brown (about 5 to 7 minutes). Do not overcook. Set aside.
On a clean pan, sauté onion in 2 tablespoons cooking oil.
Add the sauce mixture and then stir until the mixture starts to thicken.
Put-in the deep fried chicken and stir until the sauce coats each piece.
Add the chopped scallions. Transfer to a serving plate.
Serve. Share and enjoy!