Trim fat from meat. Cut small slits (about 1/2 inch wide and 1 inch deep) in meat; insert a piece 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 loosely with foil; let stand for 10 minutes (the meats temperature will rise 5 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. Makes 10 to 12 servings.