Add 2 liters of water to a saucepan with 2 roughly chopped carrots, 1 piece of celery (about the size of your big toe), 2 bay leaves, some peppercorns, and salt to taste. Bring to a boil over medium-high heat for about 10 minutes, then add the 500 g beef. Reduce heat to medium-low so the broth stays hot but not boiling.
Simmer the beef in the hot broth for 90 to 120 minutes until tender.
While the beef cooks, finely grate the horseradish into a bowl.
Melt 75 g butter in a small saucepan over medium heat for 1–2 minutes. Dust with some flour and stir for 1 minute. Gradually stir in 0.25 liter milk, then add the grated horseradish, a pinch of salt, and 1 pinch of freshly grated nutmeg. Gradually add 0.5 liter beef broth while stirring. Simmer for 2–3 minutes and adjust seasoning to taste.
About 10 minutes before the beef is done, cook 300 g ribbon noodles in salted water until tender (usually 8–12 minutes). Drain well.
Remove the beef from the broth and let rest for 2–3 minutes. Slice into serving-sized pieces.
Plate the sliced beef, horseradish sauce, and noodles. Top each plate with a spoonful of cranberries.