Place the pork in a colander and pour boiling water over the pork skin until the meat as tightened up.
Allow the pork to drain off and then dry with kitchen towels.
Mix the five spice powder with the oil until you have it fully mixed.
Place the pork belly into a roasting pan and take a small, sharp knife (a paring knife is good) and make tiny little cuts in the skin using the tip of the knife. The more tiny little holes you put in the skin, the better the crackling will turn out.
Turn the pork belly over onto its skin and score the meat with a knife at 1 cm intervals. This will help the marinade flavour the meat and also help keep the pork belly flat when cooking.
Rub the marinade into the cuts in the meat and the sides of the belly.
Turn the belly over and rub salt over the skin.
Place the pork belly in the fridge uncovered for at least 12 hours before the next stage.
When you are ready to cook the pork, preheat your oven to 200˚C and remove the pork from the fridge allowing it to come up to room temperature.
Place the pork on an oven tray with a rack, pour water into the tray and cook the pork until it has an internal temperature of 71˚C. I program my thermometer to a few degrees under this and remove the pork and rest in a warm place until it reaches the desired temperature.
Remove the pork from the oven and let it cool slightly.
Place the pork in a clean oven tray and place another oven tray on top of the pork. Press down with weights — canned food tins work well. Leave for 24 hours.
To finish the pork, remove the pork from the fridge until it come up to room temperature. Preheat the oven to 200˚C.
Place the pork in the oven and begin the reheating process.
When the pork is halfway to the desired temperature, switch the oven to the broil setting and monitor the skin of the pork. You want to reach that sweet spot where the skin has browned, bubbled and is crispy and up to temperature for serving.
Rest the pork for ten minutes in a warm place before serving.
Slice the pork belly up into pieces. Around 150 grams per person is perfect for a main course.