The sweet-tart flavor of apples is a delicious counterpoint to the rich taste of pork. Tart varieties such as Granny Smith, pippin or Fuji work best for cooking. Onion and vermouth add aroma and depth of flavor to the apple here, but shallots or red bell peppers and sherry, Port, or hard cider can produce equally tasty and nuanced dishes. I prefer to use a Dry White Wine.