Turn on the Instant Pot to the Saute function and add olive oil. Once hot, add italian sausage to the pot and allow to brown, breaking it up as it cooks. Add diced onions and garlic about halfway through and cook until translucent, around 2-3 minutes.

Add chicken stock, and then pour can of diced tomatoes in the middle of the broth. Sometimes tomatoes can cause a "burn" notice when pressure cooking, so this will help prevent that.

Set cook time to 5 minutes at High Pressure. It will take a few minutes to come up to pressure.

After the 5 minutes are up, quick release. This means changing the nozzle on top from sealing to venting. Be sure to do so with an oven mitt or towel, as the steam is very hot.

Turn Instant Pot to the saute function, once again. Add tortellini and simmer until cooked, about 5 minutes. You will know they are done because they puff up.

Add heavy cream and spinach and stir.

Taste and see if salt is needed. Serve with parmesan cheese and red pepper flakes, if desired.