Remove tendons and large pieces of fat from the meat and cut it into cubes of approximately 2 x 2 centimeters.
Peel and chop the onions and cut them into rough chunks.
Heat a large pot with the butter and brown the meat in it for a couple of minutes.
Add the onions and sauté them until they are translucent.
Pour water into the pot until the meat and onions are just covered, then add bay leaves, peppercorns, and salt.
Put the lid on the pot and bring it to a boil.
Let the dish simmer on low heat for about 1 hour.
Peel the potatoes and cut them into 2 x 2 centimeter cubes. Add them to the pot with the meat, put the lid on, and let the dish simmer for another 1 hour.
Remove the pot from the heat. Stir well so that the tender potatoes slightly mash into the meat and thicken the dish.
Season to taste with vinegar, salt, and pepper, and serve with ice-cold butter, finely chopped chives, coarse rye bread, and pickled beets.