Preheat your oven to 425°F.
This high temperature is key to achieving crispy crackling on your pork shoulder.
Pat the pork shoulder dry using paper towels.
Then, rub it thoroughly with olive oil, ensuring it covers all sides.
Mix together the sea salt, black pepper, minced garlic, and chopped rosemary.
Massage this seasoning blend evenly onto the pork surface.
Place apple slices in a roasting pan and set the seasoned pork shoulder on top.
Pour the apple cider into the pan to add moisture and flavor.
Roast in the preheated oven for 30 minutes.
After that, reduce the temperature to 325°F and continue cooking for 2.5 to 3 hours.