Sprinkle the salt over the pork, and gently "massage" it into the meat. Allow the pork to marinate for 30 minutes.
While the pork is marinating, prepare the sauce by combining the water, soy sauce, dark soy sauce and white vinegar in a bowl or measuring cup
Heat the cooking oil in a large dutch oven or pot over medium-high heat.
Add the pork belly and sear it just until the outside turns golden brown; no need to cook it all the way through at this point.
Toss in the garlic cloves, bay leaves and whole peppercorns. Stir them in with the pork
Pour the sauce mixture over the pork, followed by the sugar. Give everything a good stir.
Bring the mixture to a boil over high heat, then let it simmer (while stirring occasionally) on a low heat, partially uncovered.
Simmer the pork for approximately 45 minutes to an hour, or until the liquid is reduced by half and the pork is tender. If the liquid reduces too quickly, add a bit more water to keep the meat braising and prevent it from drying out.