Bring to a low boil, and then simmer for 3- 4 hours covered in a 250 degree oven. Check occasionally if more broth needs to be added.
Check the meat for tenderness; if done remove to a plate, turn off the oven, and place the meat in the oven to keep warm.
Remove the spices, and taste the broth. Adjust for taste with salt, pepper, and/or vinegar.
It’s not traditional, but I like to take a stick blender to blend and chop up all of the onions and bread pieces in the broth.
If you’d like the broth even thicker, you can heat it on the stove to further reduce it, or mix 1 Tbsp of corn starch with 2 Tbsp of water and a few drops of Kitchen Bouquet, stir through and bring to a low boil.
Shred the beef, and add back to the pot and stir through.
Serve over mashed potatoes with rode kool (Dutch red cabbage) or fresh green beans.