|Place thawed roast in crock pot)or frozen and cook for 12 hours).|
Mix broth, au jus, and dressing mix. Pour over roast.
Cook on low for 8-10 hours.
To serve, slice roast to 1/2 inch thickness and use broth as au jus.
The left over juice makes a delicious gravy for mashed potatoes, or as a soup base.