• Score the pork belly in one inch diagonal lines. Don’t cut all the way through to the meat, just through the skin and into the fat. I use a utility/Stanley knife for this as it’s so much easier than a kitchen knife.
• Rub liberally all over (including underneatwith salt, and rub the salt into the score lines.
• Place on a piece of paper towel on a plate in the fridge, uncovered for at least 1 hour to draw out the extra moisture.
• When ready to cook, preheat the oven to 250 degrees. Remove the pork from the fridge and pat dry. Liberally rub in the olive oil, more salt and lemon juice making sure you get it into all the score lines.
• Roughly chop the carrot, onion and celery and place in the bottom of a roasting tray. You don’t eat these, but rather sit the pork on top to get heat circulating underneath and put more flavour into the meat.
• Place in the centre of the hot oven for 30 minutes or until the skin starts to blister and dry out. Take the roasting tray out of the oven and carefully pour in the apple cider vinegar and water, taking care not to splash moisture on the crackling or yourself!
• Turn the oven down to 180C / 356F and roast for a further 50 minutes, checking after 30 minutes. Rest for 10 minutes. 

Sauce

• Drain the pan juices into a small saucepan and add the sauce ingredients. Simmer on medium heat until thickened to your liking and taste for seasoning.