Bring a pot of water to a boil and blanch the pork pieces for a few minutes, this will start the cooking process, after a few minutes, remove the pork with a slotted spoon and set aside, discard the water.
Using a non stick skillet (the slightly rounded one) add the oil and sugar on low heat. When the sugar is dissolved or melted into the oil, add the pork and increase the heat to medium and cook, turning the pieces often to get a light browning on them.
Once browned, reduce heat to a low simmer and add the cooking wine, soy sauces, and the 1 cup of water and stir the pork around a bit then cover and simmer for 45 minutes to an hour until the pork is fork tender, stirring often to prevent burning. Add additional water if the skillet is too dry.
When the pork is tender and if there is a lot of liquid in the skillet, uncover and increase the heat to medium to thicken and reduce the sauce. Then pour into a serving dish, sprinkle the spring onions on the top and serve with rice on the side.