For fan potatoes, preheat oven to 200° C. If possible, use potatoes of the same size, which should not be too large, so that they cook evenly later. Peel and wash the potatoes, place them on a tablespoon and cut them crosswise into thin slices, but do not cut them through completely. The fans of potatoes should still hang together on the underside. Grease a casserole dish lightly and place fans of potatoes with the closed side down into the dish. Push the compartments slightly apart. Season fan potatoes with salt and some paprika powder. Melt the butter at a low temperature. Pour liquid butter over the potatoes and bake in the oven for 45 to 55 minutes until golden brown. While baking, brush the potatoes with the drained butter from time to time.