Set to saute mode and add a bit of olive oil, diced onions and garlic. Cook for a few minutes just until onions begin to soften.
Turn pot off. Add half of your basil leaves and your can of tomato sauce. Stir.
Set to high pressure for 2 minutes, do a quick release.
Set Instant Pot to saute again and add in your already stuffed tortellini noodles (add 1-2 cups depending on how many you'd like in your soup).
Cook for about 5 minutes stirring intermittently until tortellinis are as tender as you'd like them.
Pour in whipping cream and stir. Cook for another 2 minutes or so, just until everything is warmed again and serve topped with additional basil, salt and/ or parmesan cheese if desired.