Season roast with salt and pepper if desired.
Sear roast in crock pot with torch or in skillet. In the crock pot with a torch is preferred so you don't lose any juices. The point is to create flavor with the Maillard reaction, not to cook it.
Put the roast in a slow cooker.
Add the butter, au jus gravy mix, ranch dressing mix and pepperoncini peppers and juice.
Cook on low until tender, about 8 hours.