One of my favorite ways to use up the pork shoulder is to shred it and put the pork shoulder into shreds with BBQ sauce on a bun. Shred up into chili, soup, and even fried rice. Like any other meat ...
For the pork layer, finely chop the pork shoulder and pork belly ... Put in a roasting tin and add just enough boiled water to reach up to 2cm/¾in up the side of the terrine.