Season both sides of the roast with salt and pepper to taste.
In a large skillet, heat the oil. When hot, add the roast and sear, about 4 minutes per side until browned.
Transfer the seared roast to the slow cooker. Sprinkle the ranch seasoning mix and the dry au jus mix on top of the chuck roast and place the stick of butter on top. Arrange the jar of Mezzetta® Golden Greek Peperoncini around the roast, brine and all. Add ½ cup of Mezzetta Cocktail Onions.
Cook on low for 8 hours or until the meat is fall apart tender. Shred the roast and serve with gravy juices.
