Bring a pot of salted water to a boil. Add pork belly and boil 2-3 minutes to remove impurities.
Remove, rinse, and scrape the skin clean (no hair, no fibers).
Flip pork belly over and score the meat lengthwise, about 1½ inches apart, not cutting all the way through.
Rub meat side with olive oil, a generous amount of jerk seasoning, and a little salt. Keep seasoning off the skin.
Flip skin-side up and poke small holes in the skin without piercing the fat.
Place on a rack and sprinkle approximately 2 tbsp salt evenly over the skin.
Let sit 20 minutes, then brush off excess salt.
Rub approximately 1 tbsp rice wine vinegar into the skin.
Refrigerate uncovered overnight until skin is completely dry.
Preheat oven to 325°F (165°C). Place pork belly on a rack, wrap foil around the sides to keep it level (don't cover the skin).
Roast 1½–2 hours, until tender.
Increase oven to 425–450°F (220–230°C) and roast 20–30 minutes until skin is puffed and shatteringly crisp.
Rest 10 minutes, then slice and enjoy.
