Pork Stock/Shredded Pork

This is a pork-based equivalent of the following recipe, but the stock is richer and more concentrated. You can easily double the recipe and freeze any stock not needed at the moment.

My favorite cut of meat for cooked shredded pork is a nice piece of Boston shoulder butt with a thin layer of fat (to keep the meat moist) and the bone in (to give body and flavor). When I need stock but not the cooked meat, I often replace the pork butt with a combination of 2 pounds pork neck bones a