Fry the onions until translucent, dust them a little with flour and add meat broth. Simmer. In the meantime, cut the liver into strips and fry briefly in a little hot oil until it is brown on the outside. Then season with salt and pepper and marjoram and deglaze with a dash of vinegar. Then pour everything into the now creamy onion sauce. Season again to taste, add gusto vinegar and finally stir in a spoonful of sour cream or yoghurt. There is also a green salad and boiled potatoes.
And the whole recipe can also be made with pork kidneys.
But of course, water thoroughly and cut out the white strands.