Procedure
1) Prepare the dough. Bring all the dough ingredients together and knead into a smooth elastic dough. Cover and let rise in a warm place until the dough has doubled in size.
2) Once the dough has risen, preheat the oven to 180C / 160C fan. Roll the dough out into a rough rectangle which is not too thick, nor it is too thin. Top the dough with the grated potatoes and add the salt to taste. Make sure the spread the potatoes so that they cover the whole dough. Next, grate the butter onto the potatoes.
3) Fold the dough a few times on itself, so that you enclose the potatoes and the butter within it. Roll the dough out again into a thicker rectangle, and using a round glass or a cookie cutter, cut out the potato cakes. Brush the cakes with the beaten egg, sprinkle with some grated cheese and bake in the preheated oven until golden brown.
4) Serve warm or cold. Enjoy!
