My DH was raised on this dish so I had to learn to make it....MIL uses the jarred dried beef. Make a white sauce using butter flour and milk...the only thing I do differently than my MIL is that I reconstitute the beef in water, this helps to remove some of the salt in the meat.
This is an expensive dish to make if you look at how much the jarred dried beef is...i prefer to make sausage gravy instead....cheaper and more filling IMHO