Put the roughly grated potatoes in a kitchen towel, fold the towel over it and twist both ends against each other until no more liquid comes out. Mix the grated potatoes in a bowl with the onion cubes, the beaten egg, a good pinch of salt and some fresh, ground pepper.
Heat oil in a large pan. Pour in the dough in portions with a large spoon and press it a little wide, so that 1 cm thick buffers are formed. Bake for 3-4 minutes on each side over medium heat until crispy and golden brown.
Served alone for breakfast or as a side dish with fried eggs and bacon.