Step 1Rub pork loin with cinnamon and season liberally with salt and pepper.
Step 2Heat oil in heavy roasting pan over moderate heat until oil begins to smoke. Sear pork loin on all sides until brown. Remove from roaster and drain excess fat.
Step 3Add potatoes and rosemary to roasting pan. Place pork loin on top. Add stock and butter. Roast in 325-degree oven, basting every 15 minutes. After 45 minutes add apples and prunes. Continue roasting, basting every 15 minutes, until thermometer inserted in center of loin reads 150 degrees, approximately 20 to 30 minutes more.
Step 4Remove from oven and cover loosely with foil. Let pork loin rest 15 minutes. While pork is resting, arrange potatoes, apples and prunes around serving platter.
Step 5Strain cooking liquid into saucepan and bring to simmer. Slice pork loin and place slices on top of potatoes, apples and prunes. Add parsley to hot sauce and spoon over pork.