Pat beef dry with paper towels and season with salt, pepper, onion powder, and garlic powder. Select SAUTE and add oil to the cooking pot.

When oil is hot, brown roast on all sides, 8 to 10 minutes. Remove to a platter when browned.

Add the chopped onions to the oil in the pot. Cook, stirring occasionally until softened, about 3 to 5 minutes.

Stir in tomato paste and mushrooms and cook, stirring constantly, about 3 minutes.

Stir in broth and simmer until slightly reduced, about 3 minutes. Scrape up all the browned bits stuck on the bottom of the pot while broth is simmering.

Put the browned pot roast and any accumulated juices in the pressure cooking pot and place potatoes and carrots on top of the meat. Lock lid in place.

Select HIGH PRESSURE and set the timer for 90 minutes. When beep sounds, turn off Instant Pot and allow pressure to release naturally for 15 minutes. After 15 minutes, use a quick pressure release to release any remaining pressure.

Carefully remove lid. Transfer potatoes and beef to serving dishes. Tent beef loosely with aluminum foil and let rest for 15 minutes before carving.

While beef is resting, strain and skim excess fat from the juices. Return juices to the pressure cooking pot, select SAUTE and thicken juices as desired to make gravy. You can use 2 tbsp arrowroot or cornstarch mixed with ¼ cup cold water as a thickener, if necessary.

Once your gravy is ready, serve and enjoy!