Place onion, celery, and parsley inside turkey cavity. Lay bacon across the breast and spread butter between the legs and body. Tie drumsticks together with string. Brush entire turkey with olive oil. Pour broth and water into pan. Bake, uncovered, at 325° for 3 1/2 to 4 hours or until a meat thermometer reads 185°, basting about every 30 minutes. Remove turkey from oven, discard bacon. Allow it to stand for 20 minutes before carving. Thicken pan juices for gravy if desired.
Note: Chicken or wild turkey is also delicious cooked this way.