Remove roast from packaging and pat dry with a paper towel. If the roast has not been scored, score at 1cm intervals, careful not to cut the meat.
Leave the dry roast in the fridge uncovered for at least an hour, but ideally overnight.
Pour boiling water on the rind and then pat dry thoroughly with a paper towel.
Rub the roast wuth 1tablespoon of vegetable oil and half a tablespoon of salt, making sure the oil and the salt penetrate the scores.
Turn down oven to 180o and cook for another 30-35 minutes per Kg.