In 5- to 6-quart slow cooker, lightly mix sauerkraut, apples, caraway seed and apple juice. With spoon, make indention in center of mixture; place pork roast in center.
Arrange potato halves around roast on sauerkraut mixture. Spread 1 tablespoon mustard over roast.
Cover; cook on Low setting 7 to 8 hours.
In small bowl, mix sauce ingredients. Remove roast from slow cooker; place on serving platter. Cut roast into slices. Arrange potatoes around slices. With slotted spoon, remove sauerkraut mixture from slow cooker; place in serving bowl. Serve roast slices and potatoes with sauerkraut mixture and mustard sauce.