Meanwhile, add the onion, apple and rosemary to the skillet. Saute over medium heat until the onions and apples are soft, about 3 to 5 minutes. Stir in the broth and vinegar. Increase the heat and boil until the sauce has reduced, about 5 minutes. To serve, place the pork on a large platter. Slice on the diagonal and put onto 4 warmed plates.

