Cut the chicken fillet into long strips of
about 1 cm wide. Set aside after cutting. Use a small bowl to combine
the water, soy sauce, egg, sherry and cornstarch. Mix until smooth. Add
the chicken into the egg mixture and mix well. Set aside for 10 minutes. Sift the extra
cornstarch and plain flour together onto a plate. Roll
each piece of chicken in the flour, coating each piece evenly, and shake
off excess Place the chicken in a single layer on a plate ready to be fried.
Heat the oil for deep-frying in a wok or pan. It is hot enough to
use when a cube of bread turns brown in it in 30 seconds. Carefully lower about 4 pieces of chicken into the oil and cook
until golden brown. Remove the chicken with a slotted spoon and drain it on paper
towels. Repeat with the remaining chicken. Let the chicken stand while
preparing the sauce.
To make the lemon sauce : Combine the lemon juice, water, sugar,
sesame seed and sherry in a small pan. Bring to the boil over medium heat, stirring until the sugar
dissolves Stir the cornstarch into the extra tablespoon water and mix to a
smooth paste. Add it to the lemon juice mixture, stirring constantly until the
sauce boils and thickens. Set the sauce aside. Just before serving, reheat the oil in a wok to very hot. Add all
the chicken pieces and fry for 2 minutes until very crisp and a rich
golden brown. Remove the chicken with a slotted spoon and drain well on paper
towels. Pile the chicken onto a serving plate, drizzle over the sauce,
sprinkle with scallion and serve immediately.