01 - Set the Instant Pot to 'Sauté' mode. Melt the butter, then add the chicken pieces. Sauté for 2–3 minutes until just starting to turn golden (do not fully cook). Add garlic and cook for 30 seconds more.
02 - Cancel 'Sauté' mode. Pour in chicken broth, scraping up any browned bits from the bottom of the pot. Add salt, pepper, and Italian seasoning.
03 - Layer the pasta over the chicken. Press lightly so the pasta is slightly submerged but do not stir.
04 - Seal the Instant Pot. Cook on 'Manual' or 'Pressure Cook' (high pressure) for 6 minutes.
05 - Carefully quick release the pressure. Open the lid, add the heavy cream and parmesan. Stir vigorously for 1–2 minutes until the sauce thickens and the pasta is fully coated and creamy.
06 - Adjust seasoning if needed. Serve immediately, garnished with chopped parsley and extra parmesan if desired.