Step 1

Pat the chuck roast dry between a few paper towels, then season all over with 2 teaspoons salt and a few good grinds of black pepper.

Step 2

Set the Instant Pot® to saute on high (see Cook's Note). Heat the oil until shimmering but not smoking, then add the roast. Cook until well browned on both sides, about 6 minutes per side. Remove to a plate using tongs.

Step 3

Add the beef broth to the pot, then scrape any browned bits from the bottom of the pot with a wooden spoon. Stir in the ranch seasoning mix until just dissolved. Return the roast to the pot (it’s okay if the roast is not fully submerged in the broth). Scatter the pepperoncini on top.

Step 4

Follow the manufacturer's guide for locking the lid and preparing to cook. Set to pressure cook on high for 55 minutes. After the pressure cook-cycle is complete, follow the manufacturer's guide for a natural release. After 10 minutes, being careful of any remaining steam, unlock and remove the lid. Transfer the roast to a cutting board using tongs, leaving the broth in the pot. Shred the beef using 2 forks, discarding any large pieces of fat.

Step 5

Use a large spoon or small ladle to skim off as much fat as possible from the pot. Add the shredded beef back to the pot and stir to combine. Serve with mashed potatoes.