Place ham hocks in large saucepan and add enough water to cover them by 2 inches. Bring to boil, then reduce heat, cover and simmer until meat is very tender, about 2 hours. Transfer hocks to medium bowl.
Boil broth until reduced to 2 cups, about 15 minutes. Remove meat from bones and discard bones. Place hock meat in medium bowl and reserved broth in separate bowl.
At the one hour mark, heat a medium pot of water to boil and add your potatoes. Cook until tender, about 18 minutes. Drain and let cool slightly. Cut potatoes in half. Sprinkle chopped parsley on the cut potatoes. Arrange sauerkraut and meats on platter and surround with potatoes. Serve with mustard and horseradish.