Boil up the kettle (full to capacity), place leg of pork on a trivet over your sink & pour the boiling hot water all over the pork.
Dry thoroughly with paper towels.
Liberally oil & massage into the skin.
Sprinkle with salt - you don't need too much.
Place pork onto a roasting trivet - which keeps it away from any juices and helps the underside to become really crisp too.
For at least the first hour of cooking, the temp of the oven has to be really really high - 220DegC (make sure your windows are open, especially if you open the oven door, or your smoke alarm/s will sound off!!
After an hour, reduce temp to around 185DegC & continue cooking to desired 'doneness'.
Remove roast from the pan and allow to stand for at least 20 minutes in a warm place. Do not 'wrap' the roast or you'll steam the crackling and it will lose some of it's crispness.
Deglaze the pan with either stock, water or wine... bring to a simmer and reduce to create delicious gravy/jus
Notes & Tips
The boiling water shrinks the skin from the scoring allowing the heat, oil & salt to penetrate, aiding the crackling process no end! enjoy!!!