Firstly, it is important that the layer of fat on your piece of pork is scored. If it’s not already, you can ask your butcher to do this or easily do it yourself with a sharp knife – simply pierce the fat but not the meat underneath and score in several places across the length of the fat.
It is also important that the fat is as dry as possible. Make sure you take your joint out of the fridge and remove any wrapping at least 30 minutes before cooking. Give it a quick wipe with kitchen roll if needs be.
Rub a good portion of salt into the fat.
Preheat your oven to 220 degrees Celsius (425 F or gas mark 7).
Weigh your meat. Cooking times for pork are as follows:
Cook at 220 for 25 minutes then reduce the temperature to 180-190 degrees Celsius (375 F or gas mark 5). Cook for 35 minutes per pound / 450g at the lower temperature. So, for example, a joint weighing 1.8kg should be cooked for 25 minutes at 220 degrees C then 140 minutes at 180-190 degrees.
Remove your cooked meat from the oven, wrap in foil and leave to rest for 20 minutes before carving.
Do not baste your joint during cooking as this will soften the layer of fat and it won’t crackle as well.
Carve and enjoy perfect roast pork with crackling! To accompany it, why not serve with perfect roast potatoes: http://www.bukisa.com/articles/401739_perfect-roast-potatoes-every-time