Begin by bringing a large pot of salted water to a rolling boil. Add the penne pasta and cook according to package instructions until al dente, about 10-12 minutes. Reserve ½ cup of pasta water, then drain the pasta and set aside.

In a mixing bowl, toss chicken breasts with Cajun seasoning, salt, and pepper. Heat a skillet over medium-high heat with cooking oil. Add the seasoned chicken, cooking for 5-6 minutes per side until golden brown.

In the same skillet, reduce heat to medium, add butter until melted, then add chopped onion, minced garlic, and diced red bell pepper. Sauté for 2-3 minutes until vegetables soften.

Pour in white wine or chicken broth to deglaze the pan, scraping up flavorful bits. Let simmer for 2 minutes, then stir in heavy cream and grated Parmesan until sauce thickens.

Add the drained pasta and cooked chicken to the skillet, tossing to coat in the sauce. If too thick, add reserved pasta water gradually until desired consistency.

Serve the pasta garnished with fresh parsley and extra grated Parmesan if desired. Enjoy!