Return the chicken to the pot. Pour in the chicken broth. Stir in Italian seasoning, salt, and pepper.
Secure the lid and set the valve to Sealing. Select Manual or Pressure Cook on High for 5 minutes.
When the cooking time finishes, allow a Natural Pressure Release (NPR) for 5 minutes, then carefully move the valve to Venting to release any remaining pressure.
Press Cancel. Stir in the heavy cream and Parmesan cheese until the cheese melts and the soup thickens slightly. Do not boil after adding cream.
Stir in spinach, if using, until wilted. Serve immediately.
Notes
If you prefer a thicker soup, mix 1 tablespoon of cornstarch with 2 tablespoons of cold water to create a slurry. Stir the slurry into the soup during the final simmering stage (Step 6) until thickened.
Use frozen tortellini by adding 2 extra minutes to the pressure cooking time in Step 4.
Shred the cooked chicken before adding the cream and cheese for a more uniform texture.