Trim fat from meat. Cut small slits (about 1/2-inch wide and 1-inch deep) in meat; insert a slice of garlic in each slit.
In a small bowl combine salt, rosemary, and black pepper. Rub rosemary mixture evenly over meat.
Place meat on a rack in a shallow roasting pan. Insert a meat thermometer into center of meat. Roast in a 325 degree F oven about 2 hours or until meat thermometer registers 155 degree F.
Meanwhile, in a large bowl, combine apples, apple juice, brown sugar, lemon juice and dry mustard. Add apple mixture to roasting pan the last 30 minutes of roasting.
Transfer meat to a serving platter. Cover meat loosely with foil; let stand for 10 minutes (the meat's temperature will rise 4 degree F during standing). Remove the rack from roasting pan. Stir the apple wedges into pan juices.
Cut the meat into slices. Serve the meat with apple mixture.