Here's a recipe from a local restaurant:
Karl Ratzsch's Sauerbraten
4 pounds beef (rump, chuck or sirloin)
2 tablespoons salt (divided)
1 cup red wine vinegar
1 cup white wine vinegar
2 cups cold water
1 onion, sliced
1 rib celery, cut coarsely
1/4 cup mixed pickling spice
1 clove garlic, crushed
2 tablespoons drippings or lard
6 to 8 gingersnap cookies, softened in a little water
2 tablespoons sugar
Equal parts of flour and water to thicken
Rub meat with 1 tablespoon salt and place it in crockpot or deep container (not aluminum). Combine vinegars, water, onion, celery, pickling spice and garlic. Pour over meat and marinate in cool place for 48 hours, turning twice daily.
Preheat oven to 400 degrees.
To roast, remove meat from crock. Heat drippings in roasting pan and sear meat on all sides. Pour marinade over meat and cover. Roast, covered, in preheated oven 20 to 30 minutes per pound, basting occasionally. Remove cover during last 20 minutes of roasting time and baste again.
Remove meat to warm platter and strain marinade into heavy kettle. Bring to boil and simmer. Add softened gingersnaps, 2 tablespoons sugar and remaining 1 tablespoon salt. Thicken to desired consistency with roux. Adjust seasonings and sugar. Slice across the grain and serve with gravy. Good with potato dumplings, buttered noodles or stewed prunes. Makes 8 to 10 servings.
http://www.jsonline.com/entree/cooking/jul02/60987.asp