in a pan combine chicken stock,orange juice,orange zest,sugar,salt,soy sauce,vinegar,ginger,onion,garlic,siracha sauce and pepper...whisk this mixture well and pour half of this mixture in the chicken and marinade for 30 mins
bring the remaining mixture to boil stirring frequently..add 2 tablespoons of cornflour with half cup of water and mix it in the sauce...reduce the heat and cook it for 1-2 mins stirring constantly until thickened..remove from heat
pour oil in a pan for frying..whisk the eggs
now take out the chicken discarding the marinated liquid..take one piece of chicken and dip in the egg and then roll it in cornflour..similarly do all the chicken pieces
now deep fry the chicken pieces till golden brown..take out in an absorbent paper
now put these chicken pieces into the sauce and again cook it for 1-2 mins until the chicken pieces are well coated with the sauce
garnish with sesame seeds and spring onions..serve hot