This is a German and Austrian specialty. In the German city Frankfurt your can find boiled beef with green sauce in almost every good restaurant. In Austria they serve the beef with a special sauce made out of apples and horseradish.
Ingredients
4 to 5 pounds beef
(first-cut flanken, brisket or chuck)
1 veal knuckle or marrow bone (optional)
1 large carrot
1 stalk celery, with leaves
1 small knob celery root, trim off straggly roots, peel and rinse
1 small parsnip, scraped and cut in half lengthwise
1 parsley root, scraped
1 onion, 2 cloves (poke the cloves into the whole onion)
1 tablespoon salt, or as needed

Cooking Instructions
- Tie the meat with a string so it won’t lose its shape.
- Place beef in a pot and add cold water (beef needs to be completely covered).
- Add the vegetable, cleaned and cut into smaller pieces to the meat (don’t cut the onion).
- Bring to a boil, then reduce heat, cover it and let it simmer for about 2 hours (until meat is completely tender; test with a fork a pointed knife).
- Take the meat and vegetable out of the broth, and keep it warm (covered with foil).
- Add salt, pepper, nutmeg to the broth and make a soup out of it by adding thin soup noodles.
- Slice the meat and place it on a warm platter, and sprinkle it with chopped parsley.
- Serve it with green sauce, boiled potatoes or fried potatoes.

Recipe for Green Sauce

In Austria they serve “Apfelkren” with the meat. Apfelkren is a mix of horseradish with apples. Here is the recipe:
¹/₂ l apple juice with a bit of vinegar
3 apples
salt, grated horseradish (add as much you like; don’t forget horseradish is very spicy)
Apfelmost (alternativ Apfelsaft mit einem Schuss Essig)

Peel apples, grate them and mix with the juice. Add salt and horseradish, mix well.

Photo credit: http://www.steirische-spezialitaeten.at