Set the Instant Pot to Sauté mode. Add olive oil and let it heat. Add the beef stew meat, seasoning with salt and pepper, and brown for about 5 minutes.
Stir in the diced onion and minced garlic, cooking until the onion is translucent (about 2-3 minutes).
Add the sliced mushrooms, Worcestershire sauce, paprika, thyme, and mix well.
Pour in the beef broth, scraping the bottom of the pot to deglaze and get all the brown bits.
Close the lid and set the valve to sealing. Switch to Pressure Cook mode and set the timer for 10 minutes. After the cooking cycle is complete, allow a natural release for 5 minutes, then quick release any remaining pressure.
In a small bowl, mix the flour and sour cream until smooth. Stir this mixture into the beef and mushroom sauce in the pot, mixing thoroughly until well combined.
Add the egg noodles directly into the pot and stir to combine. If needed, add a bit more beef broth to ensure the noodles are submerged. Seal the lid again and set to Pressure Cook for 4 minutes.
Once done, perform a quick release. Stir the stroganoff until the noodles are well coated in the creamy sauce. Taste and adjust seasoning if necessary.
Plate the beef stroganoff, garnishing with fresh parsley.