If you’ve bought a pork belly already rolled up and tied for roasting, unroll it on a cutting board and use a knife to prick the skin all over with small slits, which you should stuff with the garlic pieces.
Mix the salt, peppers and dried spices together in a bowl, massage half a tablespoon of olive oil into the pork belly, rub ¾ of the spice mix all over the pork, then sprinkle on ¾ of the chopped fresh dill, flat leaf parsley and celery leaves.
Tightly roll up the pork, re-tie it with kitchen twine, settle it on enough foil to wrap it completely, then rub another half a tablespoon of olive oil and the rest of the spice mix into the skin, sprinkle on the remaining herbs, then wrap the pork in foil, and refrigerate overnight or for at least 8 hours.
The next day, pre-heat your oven to 220°C / 430°F. Pour the rest of the olive oil into a roasting tray, unwrap your pork belly and place it at the centre of the pan, and slip the bay leaves under each corner of the pork, and slide the tray into the oven.
Roast the underside of the pork belly with the seam facing upwards for 15 minutes then turn the pork over (seam down) and roast for another 30 minutes until the skin is crispy, crackling and bubbling.
Turn the heat down to 150°C / 300°F. If the pork skin is dark brown, cover the top of the pork with a little foil so it doesn’t burn, otherwise, cover it later, and roast for 3 hours, basting the pork with its juices every hour.
If doing roast vegetables, add potato pieces one hour before the pork finishes, small purple shallots 30 minutes before, and baby carrots 15 minute before, coating the vegetables with the pork juices and sprinkling on a little salt.
When the pork is done, rest it for 30 minutes, then coat the pork and vegetables with remaining cooking juices before serving, or use the juices to make a gravy – or do both! Serve with the baked vegetables and mashed potatoes.