Season chicken slices with Cajun seasoning.
Cook penne pasta according to package instructions; drain and set aside.
Heat olive oil in a large skillet over medium heat. Add the seasoned chicken and cook until golden and nearly cooked through, about 5-6 minutes. Remove chicken and set aside.
In the same skillet, add onion and bell pepper. Cook until vegetables are tender, about 5 minutes. Add garlic and cook for another minute.
Pour in chicken broth and heavy cream. Bring to a simmer and let the sauce thicken slightly.
Return chicken to the skillet. Stir in cooked pasta and Parmesan cheese until well combined and heated through.
Season with salt and pepper. Garnish with fresh parsley before serving.
