To make, pat the pork shoulder dry with paper towels. In a small bowl, combine the oregano, chili powder, cumin, salt, and black pepper. Rub the seasoning mixture evenly over all sides of the pork.
Preheat your oven broiler to high. Line a large baking sheet with foil. Spread the shredded pork evenly on the baking sheet. Spoon about 1/2–3/4 cup of the cooking liquid over the meat to keep it juicy.