Bring a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente. Drain and set aside.

In a skillet, heat olive oil over medium heat. Add the diced onion and bell pepper, sautéing until softened, about 3-4 minutes.

Add the chicken pieces and Cajun seasoning to the skillet. Cook until the chicken is browned and cooked through, about 6-8 minutes.

Stir in the minced garlic and cook for an additional minute until fragrant.

Pour in the chicken broth and heavy cream, stirring to combine. Bring to a simmer and let it thicken for about 5 minutes.

Add the grated Parmesan cheese and stir until melted and smooth.

Add the cooked pasta to the skillet, tossing to coat in the creamy sauce. Cook for another 2-3 minutes to heat through.

Garnish with fresh parsley before serving.