Do not peel the onion, just cut it in half. Dry-fry the cut surface in a pan until dark (almost black) to give the broth colour and depth of flavour.
In a large pot, bring water to a boil with the marrow bones and washed meat.
The key to perfect Tafelspitz is using a quality top sirloin cap (Tafelspitz cut) and simmering it very slowly, just below boiling point, to keep the meat juicy and the broth clear.
It is traditionally served with three accompaniments: parsley potatoes, apple-horseradish, and chive sauce.
Do not peel the onion, just cut it in half. Dry-fry the cut surface in a pan until dark (almost black) to give the broth colour and depth of flavour.
In a large pot, bring water to a boil with the marrow bones and washed meat.
When the water starts to boil, reduce the heat to a minimum (the water should only simmer very gently). Skim off any foam (scum) that forms.
Add the roasted onion, bay leaves, peppercorns, and allspice. Simmer over low heat for 2 hours. In this phase, salt very little or not at all.
Peel the carrots, parsley root, and celeriac and cut them into large pieces. Add them to the meat and cook for another hour until the meat is completely tender (3 hours total).
Only at the very end of cooking, when the meat is tender, season the broth well with salt (salting earlier can dry out the meat).
Remove the meat and let it rest for a while. Strain the broth.
Apple Horseradish: Grate the apple finely, mix with freshly grated horseradish, and add a pinch of sugar and a squeeze of lemon juice.
Chive Sauce: Mix the sour cream/crème fraîche with chopped chives, salt, and pepper.
Slice the meat thinly across the grain.
Traditionally, the meat and some of the cooked vegetables (from the broth) are served in a deep plate, poured over with a little hot broth.
Serve with parsley potatoes, apple horseradish, and chive sauce.