Sauté Aromatics
Set Instant Pot to Sauté. Add oil/butter, onion, and garlic. Cook 2-3 minutes until softened.
Build Soup Base
Stir in crushed tomatoes, broth, Italian seasoning, salt, and pepper. (Optional but recommended: use an immersion blender to blend the soup base smooth.)
Pressure Cook
Seal lid. Cook on High Pressure for 10 minutes. Quick release when done.
Cook Tortellini
Switch to Sauté mode. Add frozen tortellini. Cook 4-6 minutes, stirring occasionally, until pasta is tender.
Make it Creamy
Stir in heavy cream and Parmesan cheese. Simmer 2-3 minutes until heated through.
Serve
Taste and adjust seasoning if needed. Serve hot with bread or salad.