Prepare the Roast: Season the chuck roast with salt and pepper on both sides.
Layer in the Crock Pot: Place the roast in the bottom of the crock pot. Sprinkle the ranch seasoning and au jus mix over the top. Add the whole pepperoncini peppers and pour in the pepperoncini juice. Place the stick of butter directly on top of the roast.
Slow Cook: Cover and cook on LOW for 8 hours or HIGH for 4–5 hours until the meat is fork-tender and shreds easily.
Shred and Serve: Remove the roast from the crock pot and shred with two forks. Return the meat to the juices in the crock pot to keep it moist. Serve over mashed potatoes, rice, or noodles, and spoon extra gravy on top.