Ingredients:

• 2 kg beef roast (such as chuck or rump)
• 1 large onion, sliced
• 2 carrots, chopped
• 2 celery stalks, chopped
• 4 cloves garlic, minced
• 2 bay leaves
• 10 whole peppercorns
• 10 juniper berries (optional)
• 2 cups red wine vinegar
• 2 cups beef broth
• 2 tablespoons vegetable oil
• Salt and pepper to taste

Instructions:

1. In a large bowl or resealable plastic bag, combine the red wine vinegar, sliced onion, carrots, celery, minced garlic, bay leaves, peppercorns, and juniper berries (if using).
2. Add the beef roast to the marinade, ensuring it is fully submerged. Cover the bowl or seal the bag and refrigerate for at least 24 hours, turning the roast occasionally.
3. After marinating, remove the beef roast from the marinade and pat it dry with paper towels. Strain and reserve the marinade, discarding the solids.
4. Heat the vegetable oil in a large Dutch oven or deep skillet over medium-high heat.
5. Season the beef roast with salt and pepper, then sear it on all sides until browned. Remove the roast from the pot and set it aside.
6. Pour the reserved marinade into the pot, scraping the bottom to loosen any browned bits. Bring the liquid to a boil and cook for a few minutes to reduce slightly.
7. Return the seared beef roast to the pot, along with the beef broth. Bring the liquid to a simmer.
8. Reduce the heat to low, cover the pot, and let the Sauerbraten simmer for about 2 to 3 hours, or until the meat is tender and can be easily pierced with a fork.
9. Once cooked, remove the roast from the pot and let it rest for a few minutes before slicing it against the grain.
10. Strain the cooking liquid and use it to make a rich gravy, if desired.
11. Serve the sliced Sauerbraten with the gravy, along with traditional sides like red cabbage, sauerkraut, and potato dumplings (Kartoffelknödel).

Note: Sauerbraten is traditionally served with hearty sides and is a popular dish during special occasions and holidays in Germany. The marinating process adds depth of flavor and tenderizes the meat.