Instructions

1. Cut beef into 1-inch cubes or strips. Season generously with salt and pepper. Select "SAUTE" to start heating the instant pot. Add 2 Tbsp of the butter and brown the meat in a single layer in the bottom. Once browned, remove to a plate and continue browning all the meat. This may take a few minutes.
2. Once all the meat is browned, add remaining 2 Tbsp butter to the pot. Add onion and mushrooms and cook for about 3 minutes, until the onions are soft. 
3. Add garlic, tomato paste, and beef broth to the Instant Pot. Stir until bits on the bottom of pot come loose. Turn off. Add meat back to the pressure cooker.
4. Secure lid and make sure the valve on top is set to "SEALING." Select "high pressure" and set for 18 minutes.
5. While the beef stroganoff cooks, prepare egg noodles according to package directions. Drain and set aside.
6. When the cook time ends, let pressure release naturally for ten minutes, then do a quick release until the valve drops. Open the lid.
7. In a small bowl, whisk the cornstarch with cold water until smooth. Add this slurry to the instant pot and select "SAUTE." Continue cooking until the sauce begins to thicken and boil (it will only take a couple minutes).
8. Remove a small spoonful of the sauce and place it in a bowl with the sour cream. Whisk together then pour into instant pot. Stir until smooth. Add cooked noodles and serve with parsley.