Press the saute button on Instant pot. Add vegetable oil and heat until hot. Add sausage and brown, stirring and breaking apart into crumbles as it cooks.
After sausage has cooked about halfway through, add the onion and cook another 3-4 minutes, until onion is soft. Add garlic and cook until fragrant, about 30 seconds.
Drain grease if needed, and return sausage mixture to the pot.
Add Italian seasoning, salt, pepper, and chicken broth, using a wooden spoon to scrape the bottom of the pot to ensure no browned bits are stuck on there.
Add tomato puree and crushed tomatoes, and give it a quick stir.
Cancel the saute function, and secure Instant Pot lid, making sure the valve is set to "sealing". Press the Pressure Cook or Manual button and use the +/- buttons to set the timer for 5 minutes.
Once the timer beeps, let out the pressure by carefully moving the valve to “venting" to perform a quick release.
When the pin drops, remove lid and set aside. Press the saute button once again, and add tortellini, spinach, heavy cream, and Parmesan cheese.
Stir and heat for about 2-3 minutes, or until tortellini is warmed through and they've floated to the top.
Serve warm, garnished with a sprinkle of extra Parmesan cheese and fresh parsley/basil.