1. In a medium-sized pot add the pork belly and enough water to cover it completely. Make sure there is some space between the water level and the lip of the pot to avoid boiling over and to make skimming easier.
2. Add the green onions and ginger. Cook over high heat until the water reaches a full boil. Boil for 5 minutes, using a fine mesh strainer (or a ladle) to skim and discard the brown foam from the top, until the liquid is clear.
3. Strain the pork and reserve the blanching liquid. Rinse the pork with running tap water to stop the cooking and rinse away any scum that may have stuck to it.
4. In a separate medium-sized dutch oven or pot (make sure it is completely dry to avoid the oil and sugar splattering), add the sugar and oil. Heat over low heat until the sugar is melted and begins to brown; look for an amber color. Try to avoid stirring the sugar while melting it. Instead, swirl the whole pot.
5. Once the caramel is a light amber color, carefully add the pork chunks by gently placing them into the caramel to minimize splashing or splattering. Depending on the size of your pot, you might need to add the pork in two batches.
6. Turn the heat up to medium-low and brown the pork in the caramel, about 1 minute on each side. Be careful not to burn the sugar.
7. Add the cooking wine and scrape with a wooden spatula to release any brown bits from the bottom of the pan. Add the reserved blanching liquid, light soy sauce, dark soy sauce, ginger, green onions, and star anise.
8. Turn to medium-high heat until the broth comes to a boil. Turn to medium-low or low heat so the broth reduces to a simmer. Cover the pot, leaving a finger-width gap to allow the steam to escape. Simmer for 1 hour and 30 minutes. Stir 2 to 3 times during the simmering.
9. If the pork has turned tender but the sauce isn’t fully reduced, remove the lid and bring the heat up to medium. Cook for another 10 or 15 minutes, until the liquid is reduced to a glaze consistency. Keep an eye on the pot during the process and stir to prevent burning on the bottom.
10. Serve the pork with the glaze over steamed rice as a main course.