In a large mixing bowl, coat the chicken in the seasoning, then mix in the beaten egg until fully coated.
Add the cornstarch/cornflour to a large shallow dish. Take a piece of chicken, coat it in the cornflour, give it a shake, then place it to one side and repeat. You could do a few at a time, so long as you make sure they don't stick and are individually thoroughly coated in the cornflour. If you run out of cornflour, just add more as needed.
Option 1 (Pan Fry): Place a large pan over medium-high heat and pour in enough oil to comfortably cover the base of the pan. Once hot (it should reach 180C/350F), spread out the chicken and fry each side for 3-4 minutes, or until golden, crisp and piping hot through the centre. You may need to work in batches. I recommend placing the cooked chicken on a wire rack or paper towels to drain off excess oil
Option 2 (Air Fry): Spread the chicken out and lightly spray it with oil. Cook at 200C/400F for 12 minutes, or until light golden, crisp and piping hot through the centre. You may need to work in batches.
Meanwhile, in a large mixing bowl, combine the bang bang sauce ingredients. Add the crispy chicken and toss until fully coated.
Serve with rice and thinly sliced spring onion, then tuck in and enjoy!