Marinate the pork, cut into bite-sized cubes, in a mixture of soy sauce and one whole egg. Obviously if you're using a whole pig, you'll need more than one egg but an egg will suffice for up to 400 grams of pork.
Cover the pork and leave to marinate for up to one hour. Heat a heavy bottomed pan with enough oil to cover the base of the pan up to one inch in depth. When ready to fry the pork, drain off any excess liquid and add at least one third of a cup of cornflour. Toss the pork in the cornflour until evenly coated. Fry the pork in the oil- start by placing the pieces of pork in a single layer in the pan (do not overcrowd the pan), leave for at least three minutes before turning. Continue turning the pork at intervals of three minutes until browned on all sides. Remove the pork from the pan with a slotted spoon, drain on kitchen towels and keep warm in an uncovered bowl. Once all the pork has been cooked, add to the sweet and sour sauce just as you are about to eat. Do not leave the pork in the sauce unless you are sat at the table and ready to tuck in. If the pork sits around in the sauce it will lose its crunchy, crispiness.
And there is the answer to a riddle that has driven me mildly insane for around twenty five years.