Wash chicken, if using thighs, cut out most of the fatty pieces. Cut in 1" cubes.

Add salt, sugar, and egg to chicken & mix well. Place covered bowl in refridgerator for at least an hour or when ready to cook.

Add cornstarch to chicken & coat well.

Heat oil in a semi-deep, but not too wide saucepan on medium heat for a few minutes until hot. When hot, cook chicken in small batches at a time, leaving space between each piece. Cook until golden brown on each side (around 3 minutes total), remove cooked pieces to a papertowel lined plate. Repeat this step until all chicken is cooked.

In a medium saucepan, add vegetable oil, heat for about 1 minute on med-low heat. Stir in a small amount of the orange zest, ginger, & garlic. Stir about 1 minute.

In a bowl, combine the rest of sauce ingredients except the cornstarch & 3 Tbsp. water. Add the sauce ingredients to a pot & bring to a boil.

In the meantime, dilute the cornstarch with water. When the sauce boils, add the cornstarch & stir until slightly thickens and gets clear. Add hot sauce of choice if desired.

Stir chicken in sauce. Remove from heat & serve.

Garnish with scallion if desired.