Put the Instant Pot on "Saute" mode and once hot, add in your oil.
Put the meat in the Instant Pot, and brown on each side for 5 minutes. So this should take 10 minutes total.
Once brown, remove from the Instant Pot and set on a plate.
Add in the onion and beef broth, and stir this around to get the bits off the bottom.
Once the bits are off. you want to add the pepperoncinis and the juice. Add in the ranch packet, butter, au jus, and beef broth as well.
Turn "Saute" mode off and then add the roast back into the Instant Pot.
Close the lid and seal the valve.
Cook on "Manual" high pressure for 55 minutes.
Allow for a 15 minute natural release of pressure once the timer is up.
Now, you can open the lid and serve the roast!