Bring a large pot of salted water to a boil. Cook the fettuccine pasta according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium-high heat.
Toss the chicken strips with the Cajun seasoning until evenly coated.
Add the chicken to the skillet and cook for 5-6 minutes, stirring occasionally, until the chicken is cooked through and lightly browned. Remove the chicken from the skillet and set aside.
In the same skillet, add the sliced red bell pepper, green bell pepper, and yellow onion. Sauté for 4-5 minutes until the vegetables are tender.
Add the minced garlic and cook for an additional 1 minute until fragrant.
Pour in the heavy cream and chicken broth, stirring to combine. Bring the mixture to a gentle simmer.
Stir in the grated Parmesan cheese until melted and the sauce is creamy.
Return the cooked chicken to the skillet and stir to coat with the sauce. Season with salt and freshly ground black pepper to taste.
Add the cooked fettuccine pasta to the skillet and toss everything together until the pasta is well coated with the creamy Cajun sauce.
Remove from heat and sprinkle with chopped fresh parsley before serving.