Lay the pork, skin-side up, on a rack in a roasting tin. Rub with oil and season with salt to your liking. This process helps the fat run out and skin to crisp.
Transfer to a preheated oven. Check your recipe for times and temperatures.
Pork belly needs a combination of slow, gentle heat to tenderise the meat, plus a shorter blast at a higher heat to crisp up the skin.
Cook at 180C/160C fan/gas 4 for 2 hrs 15 mins, then turn up the oven to 200C/180C fan/gas 6 for a further 35 minutes to crisp the crackling.
the pork should be tender when ready, this can be easily checked by piercing the flesh with a fork, remove the pork from the oven, then leave to rest for 10-15 minutes before carving.