Set your Instant Pot to the SAUTE setting. Add the olive oil and butter. Once hot, toss in the diced onion along with ½ teaspoon of salt. Sauté, stirring often, until the onion starts to soften but does not brown, which should take about 3 to 4 minutes.
Now, take your cubed beef and sprinkle it with the remaining 1 teaspoon of salt and pepper. You can either toss the beef in a bowl with the seasonings or simply mix it directly on the cutting board to save some dishes. Add the seasoned beef to the pot. Cook the beef, stirring occasionally, until it’s browned on all sides, roughly 4 to 6 minutes.
Next, stir in the dillweed, garlic powder, onion powder, Worcestershire sauce, and Dijon mustard. Pour in ½ cup of the beef broth and stir with a wooden spoon. Scrape along the bottom of the pot to ensure you loosen any stuck bits of food, which helps avoid the dreaded “burn” warning.
Add the sliced mushrooms to the pot and sprinkle the flour over the top. Stir well until everything is evenly coated.
Pour the remaining beef broth into the pot and give it a good stir. Close and seal the lid of the Instant Pot.
Cook on HIGH pressure using the Manual setting for 10 minutes. Once the cooking time is up, perform a quick release of the pressure.
When it’s safe to open, carefully lift the lid and add the egg noodles into the pot. Recover the Instant Pot, seal it again, and cook on HIGH pressure for another 5 minutes.
After the second cooking time is complete, allow the pressure to naturally release for 5 minutes before performing another quick release for any remaining pressure.
Finally, open the lid and give the stroganoff a good stir. Let it cool for a few minutes, then mix in the Greek yogurt. Serve hot and sprinkle with fresh parsley or thyme if desired.
