Set the Instant Pot to "Sauté" mode and add the olive oil. Once the pot is hot, place the beef chunks in the Instant Pot and sear on all sides. Turn off sauté mode.

Pour the beef broth into the pot and scrape any browned bits from the bottom of the pot.

Sprinkle the au jus seasoning, garlic and onion powders over the beef.

Place the butter on top of the beef and add the pepperoncini peppers and pepperoncini juice around the sides.

Close and lock the lid. Set the vent to sealing. Pressure cook on high for 45 minutes.

When the pressure cook time is up, do a 15-minute pressure release then release remaining pressure.

Transfer the beef to a bowl and shred it with two forks. Chop the pepperoncini peppers if desired.

Bring the sauce in the pot to a low boil using the sauté setting. Mix the cornstarch and water. Add it to the pot and boil until thickened.

Transfer the shredded beef and peppers back to the pot and stir into the gravy.

Serve over noodles, rice or mashed potatoes.