On a cutting board, cut chicken into cubes about 1x1inch (2x2cm) and set aside.
In a medium mixing bowl, combine salt, white pepper, cornstarch, and flour. Whisk well to combine.
Add the egg, water, and oil until it reaches the consistency similar to a pancake batter.
Soak chicken cubes to the batter and refrigerate for at least 30 minutes.
Heat oil in a wok or heavy bottom pan to 350˚F (180˚C).
Gently add the chicken and cook for 5-6 minutes until lightly golden brown.
Remove the chicken from the pan and transfer to a paper towel-lined plate to release the excess oil.
Heat a pot from a medium to high heat temperature and add the oil.
Once the oil begins to shimmer, add the red pepper flakes, ginger, and garlic, and cook for 30 seconds, stirring constantly.
Add the white sugar and brown sugar, and stir well to combine.
Put the orange juice and dissolve the combined sugar while stirring occasionally.
Add the vinegar and soy sauce, and stir to combine well.
Add the cornstarch and water together and whisk to combine. Add to the pan and stir.
Cook the sauce continuously until it thickens.
Add the fried chicken and stir until well-coated with the sauce.
Top with sesame oil.