Season the beef chuck roast with salt and pepper.
Place the seasoned roast in a slow cooker.
Sprinkle the ranch dressing mix over the roast.
Add the au jus gravy mix on top of the ranch seasoning.
Place the butter on top of the roast.
Add the pepperoncini peppers around the roast.
Cover the slow cooker and set it to low for 8 hours or high for 4 hours.
Once cooked, shred the roast with forks in the slow cooker.
Serve the shredded meat with gravy over mashed potatoes or rice.