Combine the beef broth, red wine, red wine vinegar, chopped onion, crushed garlic, thyme sprigs, bay leaves, juniper berries, peppercorns, and whole cloves in a saucepan. Bring the mixture to a boil, then reduce the heat and simmer for 5 minutes. After that, let it cool completely to room temperature.

Place the beef in a large resealable bag or a non-reactive dish. Pour the cooled marinade over the meat, then refrigerate it for 2 to 3 days, with 48 hours minimum. Turn the beef once a day so the flavor reaches all sides evenly.

Heat the oven to 350°F. Remove the beef from the marinade, pat it dry, and season it with salt.

Strain the marinade and keep the liquid, discarding the solids.

Heat the olive oil in a large ovenproof pot, brown the beef on all sides, and set it aside.

Next, sauté the onion, carrots, and celery until slightly softened.

Stir in the garlic and thyme, then sprinkle in the flour and cook briefly before adding the strained marinade and the remaining beef broth.

Bring the liquid to a simmer, then return the beef to the pot. Cover and braise in the oven for about 2 1/2 hours, or until the meat is fork-tender.

Move the beef to a cutting board and simmer the sauce on the stove.

Whisk in the crushed gingersnaps and cook until the gravy thickens. Season with salt and pepper.

Slice the beef thinly against the grain, then serve it with spaetzle, the braised vegetables, and plenty of gravy. Add sour cream if you like, and finish with chopped parsley.