Set the Instant Pot to sauté mode and add the olive oil. Once heated, add the diced chicken and season with salt and pepper. Sauté for about 5 minutes until browned on all sides.
Add the minced garlic and sauté for an additional 1 minute until fragrant.
Pour in the chicken broth and scrape the bottom of the pot to release any browned bits.
Break the fettuccine in half and add it to the pot, ensuring it's submerged in the broth. Close the lid and set the valve to sealing.
Select manual mode and cook on high pressure for 4 minutes. When the cooking time is complete, carefully perform a quick release.
Open the lid and stir in the heavy cream, Parmesan cheese, and Italian seasoning. Mix until the cheese is fully melted and the sauce is creamy.
If the sauce is too thick, you can thin it out with a bit more chicken broth or cream to reach your desired consistency. Adjust seasoning with salt and pepper as needed.
Serve hot, garnished with fresh parsley.
Notes
Adjust the thickness of the sauce with additional broth or cream as needed.