To make the sauce, bring the water to a boil in a small sauce pan. Add the orange, lemon, and ginger. Simmer for 20 minutes.

While the sauce is simmering, work on the batter. In a large bowl combine the flour, corn starch, baking powder, egg, salt, pepper, and water. Whisk until smooth. Add the cubed chicken and stir to coat each piece. Allow the chicken to sit in the batter for 15 minutes.

Once the makings of the sauce has simmered, use a sieve to remove the orange, lemon, and ginger. While the sieve containing the ingredients is over the pot, use a large wooden spoon to press any remaining juice into the pot - then discard the remnants. To the pot, add the sugar, vinegar, ketchup, and plum sauce. Give the corn starch slurry a stir, in case any of it has solidified on the bottom. Then slowly stir in the corn starch slurry to the sauce. Continue to stir until the sauce has thickened. Remove from heat and cover.

Add at least 1-inch of vegetable oil to a wok. (If you don't have a wok, use a large sauce pan). Heat the oil to 375 degrees F. Working in batches, carefully add the battered chicken, one piece at a time. Using a spider or slotted spoon, constantly turn and move the chicken to ensure even cooking. Cook for 6 - 8 minutes, until golden brown. Remove and allow to cool on a plate lined with paper towels. Continue cooking the other batches in this manner.

Serve the chicken with a side of sweet and sour sauce. (I like to serve them separately so the sauce doesn't make the battered chicken soggy). If you like, serve with rice and scallions. Enjoy!