Add the oil to a large pan and heat over a medium high heat.
Cut the chicken in to bite size chungs, about 2cm by 2cm, and add to a mixing bowl.
Add the marinade ingredients and mix well. Set aside for 15 minutes to marinate.
Mix the sauce ingredients in a bowl and set aside.
After the meat has marinated, crack in the egg and mix well.
Fill a large bowl with corn flour and add the chicken pieces in batches to toss and coat. Set aside into a sieve to remove excess flour.
Ensure the oil is hot enough. It should read 180° on a food thermometer or you can test with a wooden spoon. Putting the tip into the oil should create small, steady bubbles. Large and violent bubbles means the oil is too hot.
Add the chicken into the oil piece by piece. Fry for around 4 minutes, until browned. Keep the chicken moving the prevent it from sticking together or to the pan, and to ensure it fries evenly all over.
Remove the chicken from the oil and drain in the sieve to let the excess oil drip off. Heat a wok over medium high heat.
Add the sauce to the wok and cook for 1 minute stirring constantly, until bubbling and thickening. Add in the chicken pieces and toss to coat evenly in the sauce. Cook for another 1-2 minutes so the sauce forms a sticky glaze on the chicken.
Remove and garnish with sesame seeds and thinly sliced spring onion to serve!
