Place the chuck roast in the crock pot.
Pour the pepperoncini juice from the jar over the roast.
Scatter the pepperoncinis over the roast.
Sprinkle the Ranch powder over the roast.
Sprinkle the Au Jus powder over the roast.
Place the stick of butter on top of the roast.
Place the lid on the crock pot and set to Low for 8-10 hours, or High for 4-6 hours Cook time will depend on how big the roast is. I often cut larger roasts in half for more even cooking.
When the roast is done it will be so tender it will want to fall apart. At that point you can turn off the crock pot.
I like to use a turkey baster to remove the drippings, and add them to a fat separator, then shred the meat in the crock using two forks.
Then pour back in as much of the defatted drippings as you like. That juice has a lot of flavor, so don't be shy with it. You could also make a gravy with it.
Serve over mashed potatoes, rice, or even noodles/zoodles.