Sprinkle the onion soup mix in the bottom of the crock pot. Place the rump
roast on top of the onion soup mix. Spoon the cranberry sauce around and over
the roast. Cover and cook on LOW for 10 to 12 hours.
Remove roast from crock pot and allow to rest while you thicken the gravy.
Turn the crock pot up to HIGH.
Blend the softened butter and flour into a paste and whisk it into the gravy.
Cover and cook on HIGH for about 10 minutes, until thick.
Slice the roast into 1/4-inch thick slices and serve with the gravy. The
slices may be frozen in the gravy in plastic freezer bags.