Turn instant pot to sauté function on high and add 1 tablespoon of olive oil and mild Italian Sausage. Sauté and stir until browned about 5 minutes with lid of instant pot off. Click cancel on instant pot to turn off.
Add canned tomatoes, chicken bone broth (or chicken broth, vegetable broth), bay leaf, salt and pepper, Italian dried seasoning, garlic powder, frozen vegetables and lay cheese tortellini on top.
Close and lock lid of Instant Pot and turn the steam release handle to sealing. Press the pressure cook function and change the time to 2 minutes on high pressure. (If using frozen tortellini pressure cook for only 1 minutes on high pressure) It will take somewhere between 10 minutes and 20 minutes for the pressure cooker to come to temperature. Once Instant Pot Italian Sausage Tortellini Soup has pressure cooked it will beep and if you have it set up this way it will go to the warming function.
Hit cancel on the Instant pot and unplug from wall. Being extra super careful and keep your face and eyes away from the instant pot you are going to perform the quick release function. With a pair of oven mittens and a kitchen towel, you are going to turn the steam release handle to open and allow the steam to escape fully. It is going to let off a lot of forceful steam. When it stops steaming, the float valve should now be in the down position. (If the float valve is still up and it is difficult to turn, then it means that the instant pot is still pressurized and is NOT safe to open.)
When safe to do so, remove the lid from the instant pot. Stir in your spinach. Ladle your Instant Pot Italian Sausage Tortellini Soup into bowls and top with a little parmesan cheese if desired. Enjoy.