Rub the chicken with 1 tablespoon of the soy sauce, then put aside. Peel the rind from the lemon (taking care not to take any of the pith). Shred the lemon rind and squeeze the lemon. Combine the lemon juice, remaining soy sauce, water, sugar, sesame oil and lemon rind, stirring to dissolve sugar. Heat the oil in a wok (or large saucepan) and fry the chicken pieces until golden. Add the shredded ginger and fry for one minute. Add the lemon juice mixture, bring to the boil, then simmer for 15 minutes, or until the chicken is cooked. .

Remove the chicken from the pan and cut into bite size pieces (if using breast fillets, cut slices across the fillet but keep arranged as if intact). Mix cornflour with water then add to the sauce in the pan. Stir until the sauce thickens then spoon over the chicken. Garnish with spring onions.