Peel the potatoes and trim them to an even size. Cut into very thin slices only 2 mm thick or use a food processor with the fine slicing disc. Wash for a long time under running cold water, then dry them thoroughly on a clean tea towel. Cook in batches. Place a layer of potato slices in the base of the basket and deep fry for about 4 minutes. If you overload the basket they will stick together. Drain and season with salt or paprika. Serve.