For the Erdäpfelsterz cook the potatoes, peel and still warm press through the potato press or mash. Mix the mashed potatoes with salt and flour.
Heat lard in a large frying pan and add the potato mixture. Cook until lightly browned, turn over and brown the other side as well. Break up with a fork and brown some more.
Cut the bacon into cubes and the onion into fine rings. Fry the bacon cubes in a pan until crispy. Take out and roast the onion rings in the bacon fat.
Arrange the Erdäpfelsterz on plates and sprinkle with the bacon cubes and the onion rings.