Cut the pork belly into ¾ inch slices. Cut each slice into pieces about two inches wide.
Thread the pork pieces with bamboo skewers, three to four pieces per stick.
Spread non stick paper on the bottom of a wide shallow pan. Arrange the skewered pork in a single layer.
Pour in the vinegar and soy sauce. Add the garlic, peppercorns, bay lead and oregano. Bring to the boil then lower the heat, cover the pan and simmer the pork for about 30 minutes per side.
Cool the pork in the remaining sauce.
Heat the grill. Very high temperature is essential. Lay the skewered pork adobo on the grill and cook for two minutes per side. That should be just enough time to char the surface of the meat and allow the fat to turn a little crisp. Brush with simple syrup and grill for another few seconds.
Serve the grilled pork adobo over rice or with beer.
Or serve with nothing else. It's perfect by itself anyway.
Notes
If making a huge batch of grilled pork adobo, you can use a baking tray. Line with non-stick paper, lay out the skewered pork, add the seasonings and spices, cover the tray tightly with foil and bake in the oven for about an hour at 325F.If you're cooking for a crowd, you can chill the pork after it has cooled. No need to transfer to another container and no need to pour off the remaining sauce. Just keep tightly wrapped with foil. The skewered pork adobo must be brought down to room temperature before grilling.