Turn Instant Pot onto saute. Add oil and heat for one minute. Add in onion and saute until soft, about 3 minutes.
Sprinkle beef with 1 tsp salt and pepper. Add beef to pot and cook until browned on all sides, about 2-3 minutes. Add in garlic, rosemary and paprika. Stir to combine.
Add in Worcestershire sauce and salt. Add in mushrooms and flour. Stir until combined.
Pour in beef broth and stir. Lock on lid and set to high pressure for 10 minutes. (will take about 10-15 minutes to come up to pressure)
When the timer goes off, carefully do a quick release, open pot and add in egg noodles. Close and lock and set timer for another 5 minutes at high pressure (it will take about 5 minutes to come back up to pressure)
Release pressure naturally for five minutes and then do a quick release. Open and stir in sour cream