Cut the chicken breasts into bite-size pieces. Slice the smoked sausage.
Add the chicken pieces with the olive oil, Cajun seasoning and garlic powder into the Instant Pot insert. Using the Saute mode of your Instant Pot, saute for 4 to 5 minutes, tossing often. Press Cancel twice to turn it off.
Add in the sliced sausage, small shell pasta and then the chicken stock. Gently stir and get all of the pasta to be "underwater." Add a little more water, if needed, to get the pasta to all be covered by the liquid.
Set to Sealing.
Cooking on Manual, High, for 7 minutes.
Let naturally release at least 5 minutes, then release remaining pressure.
Give the cooked pasta, chicken and sausage a gentle stir.
Then stir in the cream, Parmesan cheese and shredded mozzarella. Stir through and keep on warm mode until ready to serve.
Prepare the salad.
Serve Instant Pot Chicken & Sausage Alfredo Skillet with side salad.