Put the pork belly in a wok containing enough boiling water to cover the meat completely. Continuously skim off the scum as it forms on top of the boiling water. Boil for about 20 minutes then drain the pork belly and place on a plate to cool. The boiling liquid can be reused for braising after filtering through a fine sieve. When the pork belly is cool to touch cut it into pieces of about 1.5 inches cubes.
Melt the sugar and the vegetable oil in a wok over medium high heat. Continue heating until the sugar is slightly brown. About 3 minutes. Add the cubed pork belly and brown it with the caramelized sugar. About 8 minutes.
Put the garlic, scallion, star anise, dark soy sauce, soy sauce, rice wine and clear stock into the pot. Cover the pot and simmer over low heat. Cook for about 90 minutes. Stir the meat every 10 minutes to make sure the pork at the bottom of the pot does not get burnt. Remove the cover and turn the heat to medium high. Cook the meat for another 10 minutes until the sauce reduces to a smooth consistency.
You can serve this dish right away or keep overnight and reheat the next day before serving. Plate it in a shallow bowl and garnish with shredded scallion and sprigs of cilantro.