You can add Italian sausage if you like. Just crumble it and saute it lightly after you saute the garlic.
I used fresh four-cheese tortellini that I found in the chilled section at the supermarket with all of the fresh pasta. I cooked it on a gentle simmer (not boil) for 5 minutes (according to the package instructions). If you cook it for too long, the tortellini parcels might explode so always read the package instructions and cook accordingly.
I like to use baby spinach leaves, but if you’re using ordinary spinach then chop it roughly before adding it to the soup.
To make this soup vegetarian omit the chicken, and use vegetable stock, but there won’t be a need to pressure cook anything.
If you end up substituting the heavy cream with half and half, the soup might be thinner and might need more cornstarch slurry to thicken (see note below).
I thickened the soup with a cornstarch slurry, I added 1 tablespoon of cornstarch mixed with 1 tablespoon of water and it was enough to thicken the soup and give it a creamy consistency. You might need more especially if you use half and half instead of heavy cream.