Preheat oven to 350 degrees F. Lay a large sheet of Reynolds Wrap® Heavy Duty Foil on a baking sheet. In the center of the foil, combine the sausage, onion, sauerkraut, oil, butter, pepper and caraway seeds mix well. Bring up foil sides. Double fold top and ends to make a packet, leaving room for heat circulation inside. Place the foil package in preheated oven and roast for 30 minutes.
Open packets carefully by cutting along top fold with a sharp knife, allowing steam to escape then open top of foil packet. Stir in the green apples and reseal, adding another piece of foil to the top if necessary. Return to the oven for 10 more minutes. Remove from the oven, add salt to taste and serve.