Preheat oven to 350 degrees. 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 for each meat. Remove the meats from the oven and let cool for 20 minutes. Cover and refrigerate up to one day or until ready to use.
Recipe courtesy of City Tavern