First I combined the seasonings together for Ray's dry rub. The recipe called for a quick dry rub for the boneless pork shoulder. I generously poured a mix of smoked paprika, salt, pepper ...
However long you plan to roast your pork shoulder for, a generous rub of sea salt into the scored skin and a blast of 30 minutes in a hot oven (220C/425F/Gas 7) should ensure a crisp crackling.