Preheat oven to 350 and grease a baking dish or dutch oven. Place roast in the baking dish and add liquid of your choice, pepperoncini juice is best. Sprinkle roast with au jus and dry ranch seasoning. I alternated between the two.
Top with pats of butter and peppers. Cover with foil. Roast for 2 hours or until it shreds easily with a fork. When cooking is complete, remove from oven and let rest for 10 minutes.
Use 2 forks to shred the roast and mix well with juice. Serve roast with mashed potatoes and additional pepperoncini peppers if desired.