"This sour beef dish was often cooked by my German grandmother. It is perfect for any Oktoberfest celebration and is sure to get many rave reviews. My wife was not so hot on the idea of sour beef until she tried it in Germanland in Epcot Center. Serve with potato dumplings, potato pancakes or boiled potatoes (or boiled cauliflower)."
Wipe beef with a damp cloth and season with salt and pepper. Place seasoned beef in a large glass bowl.
Combine vinegar, carrots, onion, peppercorns, cloves, bay leaves, and parsley in a bowl; pour over beef. Cover dish tightly with a lid or plastic wrap.
Refrigerate beef, turning daily, for 3 to 7 days.
Drain meat, reserving liquid and vegetables. Rub flour over all sides of beef.
Heat butter in a large Dutch oven over medium-high heat; brown beef on all sides, 5 to 10 minutes. Add onions, carrots, and 2 cups reserved liquid. Cover Dutch oven, lower heat to medium-low, and simmer until meat is tender, about 2 hours. Transfer beef to a serving platter.
Stir gingersnap crumbs and sugar into the liquid in Dutch oven; cook and stir until sauce is thickened, about 5 minutes. Pour sauce over meat.