Spray Instant Pot interior with cooking spray. Set to saute.
Drizzle about a Tablespoon of cooking oil (I used olive) and brown ground beef or turkey, onion, and garlic.
Drain excess grease and return to pot.
Add mushrooms with saute another minute or two.
Add water, onion soup, and salt and pepper. Mix. Whisk in cornstarch
Place lid on Instant Pot.
Set to high pressure for 6 minutes.
After it is done, let the pressure naturally release for about five minutes, and then change to quick release until all the pressure is gone.
Stir in Greek Yogurt until combined. Enjoy!