Prepare the pasta according to the instructions on the package until it is al dente. Reserve one cup of the pasta cooking water before draining.
Cut the chicken into small bite-sized pieces then season with half of the Cajun seasoning, plus salt and black pepper to taste.
Warm the olive oil in a large pan over medium-high heat and cook the chicken until it turns golden brown and is fully cooked, about 6 to 7 minutes, then set it aside.
Using the same pan, melt the butter and sauté the minced garlic, diced onion, and sliced bell peppers until they soften, around 4 to 5 minutes.
Pour in the chicken broth to deglaze the pan, scraping the bottom to lift up any flavorful browned bits.
Add the heavy cream and the remaining Cajun seasoning, gently simmer the mixture for 3 to 4 minutes allowing it to thicken slightly.
Stir in the Parmesan cheese until it melts smoothly into the sauce.
Return the cooked chicken back to the skillet and toss in the pasta, combining everything thoroughly. Add the reserved pasta water as needed to reach your desired sauce consistency.
Sprinkle the chopped fresh parsley over the top and serve right away with extra Parmesan cheese if you like.
