Preheat oven to 350 degrees F. Place the apples on the bottom of a 13 by 9-inch glass baking dish. Place pork tenderloin on top of apples. Pour about 1/2 cup of plum sauce over pork and apples. Cook until pork reaches an internal temperature of 125 degrees F. Pour on more sauce, about 1/2 cup, and cook until internal temperature is 135 degrees F. Remember that meat continues to cook after you remove it from the oven.
Recipe courtesy of Truffles and Trifles, Orlando, Florida