In a large pot, bring salted water to a boil. Add the fettuccine and cook according to the package instructions until al dente. Drain and set aside.
Season the sliced chicken breasts with Cajun seasoning, ensuring each piece is evenly coated.
In a large skillet, heat the olive oil over medium heat. Add the seasoned chicken and cook for about 5-7 minutes, or until cooked through and golden brown. Remove the chicken from the skillet and set aside.
In the same skillet, add the chopped onion and bell pepper. Sauté for 3-4 minutes until the vegetables are softened. Add the minced garlic and cook for an additional minute until fragrant.
Pour in the chicken broth and bring to a simmer. Stir in the heavy cream and let it bubble gently for 2-3 minutes until slightly thickened. Then, add in the grated Parmesan cheese, stirring until melted and creamy.
Add the cooked chicken and fettuccine to the sauce mixture. Toss gently to coat everything in the creamy Cajun sauce. Season with more salt, pepper, or Cajun seasoning to taste if desired.
Remove from heat, transfer the pasta to serving plates, and sprinkle with fresh parsley for a pop of color.
Notes
Adjust the Cajun seasoning to your spice preference.