This is a delicious recipe in which I share my tips on how to make perfect slow roast pork using Old Hall Farm rare breed pork shoulder, with crispy mustard crackling, beef dripping potatoes, and an apple and mustard sauce. Before I begin, I have to be honest. This was hands down the best pork joint I have ever had. The flavour from Old Hall Farm’s rare breed pork was incredible, and the slow cook resulted in a beautifully tender piece of meat. I shared a photo with a British friend who lives in America; she is still crying as…