Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   3      pounds        Beef Chuck Roast
     1/2  cup           ketchup
     1/2  cup           Water
   2      tablespoons   sugar -- white or brown
   1      tablespoon    vinegar
   1      medium        onion -- chopped

Preparation:

Place beef in crock pot. Combine all remaining ingredients in a bowl and pour over meat. Cover and cook on low for 11 to 12 hours (or on high for 5 to 6 hours). Break up and shred meat with a fork, mix and serve on hamburger buns. This easily makes a dozen or more sandwiches, depending on how filled and sloppy you like them. I also make a double batch and freeze half of the filling for a quick dinner in the future.