The picnic shoulder is among the tastiest of pork roasts. Try to find a whole picnic roast with the skin left on. Brushing it with water during roasting keeps the skin tender enough to eat. If your knife is not sharp enough to score the skin, a box cutter fitted with a fresh blade works well.
Gather the ingredients for:
Instead of simmering, add the mojo ingredients to a blender or food processor and puree until smooth. Have ready:
Using a very sharp knife, slice through the skin at 1-inch intervals in a crosshatch pattern; try not to cut into the meat underneath. Push your fingers between the muscles exposed on the cut side of the roast and work them open so that more of the interior will be exposed to the marinade. Place the roast in a bowl just big enough to fit it, or in a large zip-top bag or oven bag set in a baking dish. Add the marinade, cover the bowl or close the bag, and refrigerate overnight and for up to 2 days. If the pork is not fully submerged in the marinade, turn it several times so that all sides are equally exposed.
Preheat the oven to 350°F.
Drain the marinade into a bowl and set aside. Pat the roast dry and place on a rack in a roasting pan. Roast until a thermometer inserted in the center registers 185°F, 4 to 4 ½ hours, brushing the skin every 30 minutes with cold water.
Transfer the roast to a cutting board, cover loosely with foil, and let stand for 20 minutes. Meanwhile, skim off the fat from the pan juices. Place the roasting pan over 2 burners on medium-high heat and add the reserved marinade. Bring to a boil, scraping up the browned bits on the bottom of the pan. Once deglazed, transfer the marinade to a saucepan and simmer for an additional 5 minutes, or until the sauce has thickened to your liking. Season to taste with:
Remove the crispy squares of skin and slice the meat; arrange the slices on a platter and pour the sauce over them. Arrange the cracklings around the meat and serve.