Season the chuck roast with salt and pepper.
Heat a skillet over medium-high heat and sear the roast on all sides until browned.
Place the browned roast into the slow cooker.
Sprinkle the ranch dressing mix evenly over the roast.
Add the au jus gravy mix on top.
Pour the pepperoncini peppers and their juice over the roast.
Place the stick of butter on top of the roast.
Cover the slow cooker and cook on low for 8 hours.
Once done, shred the meat with two forks directly in the cooker.
Stir to combine the meat with the juices before serving.