Pat the pork belly skin dry with a paper towel.
Leave the pork belly uncovered in the refrigerator overnight to dry out properly.
Rub a generous amount of oil over the pork belly, coating every inch.
Season the flesh with your preferred spices, avoiding seasoning the skin.
Wrap the seasoned pork belly in foil, leaving the skin exposed for direct heat contact.
Preheat the oven to 150°C (300°F) and place the foil-wrapped pork belly on a baking sheet.
Slow roast for approximately 2 1/2 hours to render the fat and cook the meat.
Remove the foil and place the meat on a wire rack.
Use balls of foil to level any uneven areas for consistent crackling.
Preheat the oven to 220°C (425°F) and place the leveled pork belly on the wire rack.
Cook for an additional 30 minutes under high heat for crispy crackling.