For the Instant Pot, set it to sauté mode, adding olive oil and minced garlic; sauté for about 1 minute until fragrant.
Season the chicken breasts with salt, pepper, and Italian seasoning, then add them to the pot and sear on both sides for about 2-3 minutes.
Pour in the chicken broth, close the lid, and set the valve to sealing.
Cook on high pressure for 10 minutes, then carefully release the pressure.
Remove the chicken and set aside, stirring in the heavy cream and Parmesan cheese into the pot until smooth.
Add the spinach and return the chicken to the pot, cooking for an additional 2-3 minutes until heated through.