Set Instant Pot to Saute on Hot.
Once the Pressure Cooker is hot add the oil, wait for it to sizzle.
Add the ground beef, let it cook without moving for about 1 minute, to get a nice sear on it. After that, break it up using a wooden spoon as it cooks.
Once the ground beef has browned and is no longer pink add onion, garlic and mushrooms. Stir and cook for another 1-2 minutes.
Add the red pepper flakes, dried thyme, ground mustard, and dried parsley. Add some black pepper and salt. Stir to combine.
Then, add Worcestershire sauce, beef consommé, and beef broth. Scrape the bottom of the pot with a wooden spoon, to make sure bits are not stuck to it.
Next, add egg noddles, and gently stir a little, not much. Pour one cup of water on top and again gently stir to submerge them slightly not entirely into the liquid.
Cover and seal the lid. Make sure the valve points to Sealed. Change the setting to manual and adjust the time to 5 minutes on High Pressure.
Once the Instant Pot beeps to show that it's done, do a quick release, by changing the position of the valve to Vent. Carefully remove the cover.
Select Sauté mode on Medium Hot.
In a cup combine cornstarch with the 4 tablespoons of water until fully dissolved.
Add the sour cream to the pot, add the cornstarch mix and gently stir to combine, until sour cream is fully melted.
Add salt and pepper to taste.
Garnish with fresh parsley and serve.