Cook the Pasta: Bring a large pot of salted water to a boil. Add penne and cook until tender. Drain well and set aside. Keep the pasta dry so the sauce sticks better later.
Season the Chicken: Place chicken pieces in a bowl. Sprinkle with cajun seasoning, salt, and pepper. Toss until each piece gets coated evenly. This step builds flavor early.
Sear the Chicken: Heat olive oil in a large skillet over medium heat. Add chicken in a single layer. Cook until golden and cooked through. Remove and set aside.
Brown the Sausage: Add sausage slices to the same skillet. Cook until edges turn lightly crisp. The smoky flavor deepens the base of the sauce.
Build the Sauce: Lower heat slightly and add garlic. Stir until fragrant. Pour in half and half and stir slowly. Let it warm without boiling.
Melt the Cheese: Sprinkle parmesan into the sauce while stirring. Keep stirring until the sauce thickens and turns smooth.
Combine Everything: Add cooked pasta and chicken back into the skillet. Toss gently until everything coats in sauce. Finish with parsley.
