Step 1

Cut 1 stick unsalted butter into 8 pieces. Trim off any large pieces of surface fat from 1 (3-pound) boneless beef chuck roast. Pat dry with paper towels.

Step 2

Heat 1 tablespoon vegetable or canola oil in a 6-quart or larger Instant Pot or electric pressure cooker on the highest Sauté setting until shimmering. Add the roast and sear on all sides until browned, about 10 minutes total. Transfer to a plate.

Step 3

Pour 1/4 cup water into the pressure cooker, scrape up any browned bits, and simmer until almost evaporated, 1 to 2 minutes. Turn off the pressure cooker.

Step 4

Return the roast and any accumulated juices to the pressure cooker. Sprinkle the roast with 1 packet ranch mix and 1 or 2 packets au jus gravy mix. Top with the butter. Pour 1/2 cup brine from 1 jar pepperoncini peppers over the roast. Add 10 pepperoncini peppers.

Step 5

Lock the lid on and make sure the pressure valve is set to seal. Set to cook under HIGH pressure for 55 minutes. It will take about 15 minutes to come up to pressure.

Step 6

When the cook time is up, let the pressure naturally release for 15 minutes. Quick release any remaining pressure. Shred the roast into bite-sized pieces with tongs.