Grate both types of cheese. Peel and finely chop the onion. Cut the chives into fine rolls.
Heat some butter in a pan and fry the onions in it. Let cool a little.
In the meantime, whisk eggs with milk and mix with the bread cubes, cheese, marjoram, salt and pepper. Leave to stand for at least 15 minutes.
After that, form loafs from the diced bread and cheese mixture and fry them in a little oil on all sides.
Meanwhile, heat the soup.
Place the cheese dumplings on plates, pour the soup over them and sprinkle with chives.