For the potato croquettes, remove the peel from the potatoes, cut them into equal-sized pieces and soften them in enough salted water. Steam the water and the potatoes well. Shake the pot repeatedly so that the potatoes lose as much water as possible.
Press the potatoes through a potato ricer, mix with egg yolk and season with salt, pepper and a pinch of nutmeg. Shape the potato mixture on a well-floured surface into even rolls about one and a half cm in diameter and cut them into pieces about four cm long. Turn the individual rolls first in flour on the other side, then pull them through beaten egg and coat with breadcrumbs.
Just before serving, fry the croquettes in a saucepan with heated oil until golden brown, then drain briefly on kitchen roll.
Or form them into flat croquettes on the spot from the beginning and fry them in a frying pan with as little oil as possible on both sides.
Season the steaks with pepper, season with salt, rub with crushed caraway seeds (or not, pure matter of taste) and sear in a frying pan with a little olive oil, over medium heat on each side well, but not too much, since the steaks will be after-cooked – and likewise still over-baked. Remove the meat from the frying pan, wrap it in aluminum foil and let it rest for at least about five minutes.
In the meantime, for the sauce, sauté the onions in the meat pan.