Mix together the Cajun spices in a small bowl. Set aside for later use.

Bring a large pot of salted water to a boil. Cook the penne according to package directions until it reaches an al dente texture. Drain and set aside.

In a large skillet, heat the olive oil and butter over medium-high heat. Season the sliced chicken with 1 1/2 teaspoons of the Cajun seasoning blend.

Cook the chicken in the skillet until it is browned and fully cooked, then transfer it to a plate and set aside.

In the same skillet, add the diced onion and sliced bell peppers. Sauté for 3-4 minutes until they become tender.

Add the minced garlic to the skillet and cook for about 1 minute until it becomes fragrant. Stir in the remaining Cajun seasoning.

Pour in the heavy cream and bring the mixture to a gentle simmer. Let it cook for around 5 minutes until the cream starts to thicken.

Return the cooked chicken and penne pasta to the skillet, mixing everything together to ensure the pasta is well coated with the creamy sauce. Add the grated Parmesan cheese and stir until it is fully incorporated.

Serve the pasta in bowls, optionally garnished with fresh chopped parsley and extra grated Parmesan cheese.