Season chicken pieces with salt and pepper.
Whisk together flour and cornstarch in a bowl.
Dip chicken in beaten egg then dredge in cornstarch mixture.
Deep fry until golden and set aside, draining any excess oil.
Heat vegetable oil in a separate pan. Sautee ginger and red pepper flakes until aromatic.
Whisk all remaining ingredients for the sauce in a bowl.
Add into the pan and bring to a simmer, whisking constantly.
When sauce is thickened, add chicken into the pan and toss until evenly coated.
Garnish with fresh chopped spring onions.