Press the sauté button on the Instant Pot and adjust to high.
Toss meat with salt, pepper, paprika, and thyme. Shake or toss until evenly coated.
When the Instant Pot reads HOT, add 1½ tablespoons olive oil to the pan, and then sear meat for 3 minutes per side. Remove from heat into a separate bowl.
Add butter, chopped mushrooms, onion, and garlic to the Instant Pot and saute for about 3 minutes.
Pour in beef broth and scrape everything off the bottom of the pan.
Add the meat and any juices from the reserved bowl, then mix.
Turn off sauté mode, lock the lid, and turn the knob to sealing.
Pressure cook for 30 minutes on high pressure with a 10-minute natural pressure release.
Remove the lid, and press sauté again to bring to a boil.
Mix together cornstarch and cold water to make a slurry. Stir into the boiling mixture and stir until thickened.
Turn off sauté mode, then add sour cream.
Serve over egg noodles, rice, or mashed potatoes. Enjoy!