Preheat oven to 350 degrees F. Get a large oven safe dutch oven pot heating over high heat.
Add vegetable oil to pot and sear roast until browned, about 3 to 4 minutes each side.
Once seared, remove from heat and pour in beef broth, pepperoncinis, pepperoncini juices, and sprinkle roast with ranch dressing mix and onion powder. Add butter on top of roast.
Place a lid on the pan and transfer it to the preheated 350 degree oven. Cook 3 hours, or until meat reaches an internal temperature of 202 degrees F and shreds easily with a fork.