Sprinkle the roast with salt and pepper and rub in thoroughly. Place in a deep bowl. Add the onion, bay leaves and peppercorns. Combine 2 cups of water, vinegar and sugar in a saucepan and bring to a boil. Pour over the roast to cover. Cover bowl tightly. Refrigerate for 3 - 4 days, turning occasionally. remove from the marinade and reserve the marinade, then pat the roast dry. Brown on all sides in the shortening in a Dutch oven. Add 1 cup of the reserved marinade, then cover and simmer until tender, adding marinade as needed. remove the roast to a warm platter. Add 2 cups of reserved marinade to the pan dripping and season with salt, then stir in the gingersnaps. Heat thoroughly, stirring constantly, then stir in the sour cream. Serve with the roast. 

A very old recipe