rinse pork with cold water and pat dry

place in a large roasting pan

make a paste with mustard, salt, pepper and garlic salt

rub roast with paste, messaging the paste into the skin

cover and cook at 350 degrees for 4 hours, reduce heat to 300 and cook additional 2-4 hours.

Note: be sure to add more water if the bottom of the pan becomes dry

The roast will done after about 5 hours but the continued cooking time only makes the roast more tender and reduces the fat to a crisp layer.