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.
For the pork, in a small bowl, mix the salt and sugar until combined. One to three days before you plan to grill, generously sprinkle the salt-sugar rub over the entire pork shoulder, covering ...
Rub the dry rub all over the pork, wrap in plastic wrap ... cut each sandwich in half. Serve at once. Recipe from Wine Bites by Barbara Scott-Goodman/Chronicle Books, 2011.