Heat an Instant Pot onto SAUTE. Add approximately 1 tablespoon olive oil to the inner pot when display reads HOT. Season the roast on both sides with garlic powder and pepper. Add to pot and sear on both sides.

Remove roast from pot and set aside. Deglaze the pot with the beef consommé, using a spatula or wooden spoon to scrape up any bits off the bottom of the pot. 

Add the mushrooms to the pot, then place the beef on top. Sprinkle with the onion soup mix and then top with the cream of mushroom soup. Lock lid in place, ensure valve is set to SEAL, and set pot for HIGH pressure for 50 minutes. 

After timer has counted down, allow to naturally release for 10 minutes, then quick release the remaining pressure. Use forks or tongs to shred beef. 

Gently stir in the bag of noodles. Turn machine off, then back on the SAUTE setting. Simmer for 5-10 minutes, until noodles are tender. Stir in the milk and serve over mashed potatoes.