Preheat oven to 350 degrees F.
In a small bowl, mix together the oil, salt and pepper. Rub the oil mixture over the meats. Roast the pork shoulder about 1 hour; roast the beef chuck about 1 1/2 hours, until a meat thermometer registers 170 degrees F for each meat. Remove the meats from the oven and let cool for 20 minutes. Cover and refrigerate up to 1 day or until ready to use.
Recipe courtesy of City Tavern, Philadelphia