Make the sauce by combining all ingredients in a small dish. Cover and keep chilled.
In a medium mixing bowl combine the potato, apple, sauerkraut, green onions, and eggs, toss well.
Sift the flour, salt, and white pepper in to the mixture. Stir to combine.
Scoop out ¼ cup balls of the mixture and place on a baking sheet. Form into patties, by pressing between your palms.
Heat the oil in a 12 inch skillet over medium heat until shimmering. Add 5-6 patties at a time and fry until dark golden brown on one side, then flip and cook until well browned on the other side. (about 5-6 minutes per side) Remove from pan and drain on paper towels or a wire rack. Repeat with remaining mixture.
Serve drizzled with some of the sauce, plus more for dipping and a sprinkling of green onions.
