In a large bowl, combine the ingredients of marinate. Add the chicken, stir well and marinate the chicken for 2 hours.
Add enough oil to a large sauce pan over high heat until the oil reaches 175℃. Reduce the heat to medium.
Combine the egg with 2 tbsp cold water, stir well. Place the potato starch in another bowl next to it. Dip each chicken cutlet into the egg wash, then dust by the potato starch. Shake off any excess. Fry until very golden brown on one side, about 2 minutes. Carefully flip and fry to brown the other side for another 2 minutes. Drain the chicken out with a slotted spoon and transfer to a plate lined with paper towel.