Start by sautéing the chicken and sausage in oil, just until the meat is browned on all sides. .
Add the onion, celery, garlic, and red pepper. Stir and sauté for about 2 minutes, just until the vegetables are soft and fragrant. Sprinkle in the Cajun Seasoning and stir to combine and fully coat the meat and vegetables.
Pour in the chicken broth, then the pasta.
Seal the pressure cooking lid, making sure the valve is set to SEAL, select Pressure Cook on high, set the time to 5 minutes, and start. If you're using the Ninja Foodi XL or the 8 quart Instant Pot, it usually takes about 10 minutes to come to pressure before it starts cooking.
When cooking is complete, allow to natural release for 5 minutes, then use long tongs or a wooden spoon to move the valve over to VENT for quick release. When the unit has finished releasing all pressure and the pressure release valve is all the way down, carefully twist open the lid.
Pour in the cream and parmesan cheese, and stir together.
Notes
If your sauce is thin, consider switching to Sauté for a minute or two to help thicken up the sauce.Dairy-free options: