Place the beef rump roast, which should be at room temperature, into the slow cooker. This helps the roast cook more evenly and stay tender.

Sprinkle the ranch dressing mix and au jus gravy mix evenly over the top of the roast. Arrange the pepperoncini peppers around and on top of the roast, then place the butter slices across the surface. I like to use a good-quality butter like Kerrygold for extra flavor.

Pour 1/4 cup of the juice from the pepperoncini jar into the bottom of the slow cooker, being careful not to pour directly over the roast so the seasonings stay on top. Cover the slow cooker and cook on low for 6 to 8 hours. For a roast that’s perfect for slicing, check at 6 hours; for a roast that shreds easily, cook for about 8 hours.

Once the roast reaches an internal temperature of about 160°F and is fork-tender, remove it from the slow cooker. Let it rest for at least 15 minutes before slicing or shredding to keep it juicy. I like to let it rest tented with foil, which helps preserve moisture.