Categories: Meats, Cookies 
      Yield: 10 servings 
  
      4 lb Rump Roast; Beef, Boneless        1/2 c  Cider Vinegar 
      2    Onions; Thinly Sliced             1/4 c  Vegetable Oil 
      8    Peppercorns                       1/2 ts Salt 
      4    Cloves; Whole                       2 c  Water; boiling 
      1    Bay Leaf                           10    Gingersnaps 
      1 c  White Vinegar; Mild               1/2 c  Sour Cream 
      1 c  Water                               1 tb Unbleached Flour 
  
  Place the beef roast in a deep ceramic or glass bowl. Add onions, 
  peppercorns, cloves, and bay leaf.  Pour white vinegar and cider vinegar 
  over the meat; chill, covered, for 4 days. Turn meat twice each day. Remove 
  the meat from the marinade, dry it well with paper towels, and strain the 
  marinade into a bowl.  Reserve onions and 1 cup marinade. In a Dutch oven 
  brown the meat on all sides in hot vegetable oil. Sprinkle meat with salt. 
  Pour boiling water around the meat. sprinkle in crushed gingersnaps, and 
  simmer covered for 1 1/2 hours. Turn often. Add 1 cup of reserved marinade 
  and cook meat 2 hours or more, until tender. Remove the meat and keep it 
  warm.  Strain the cooking juices into a large saucepan. In a small bowl mix 
  sour cream with flour.  Stir it into the cooking juices and cook, stirring, 
  until sauce is thickened and smooth. Slice meat in 1/4 inch slices; add to 
  hot gravy. Arrange meat on a heated plater and pour extra sauce over it.