Bring a large pot of salted water to a boil. Add fettuccine pasta and cook according to package instructions until al dente. Drain and set aside.
In a large skillet, heat olive oil over medium-high heat.
Toss chicken strips with Cajun seasoning until evenly coated.
Add the seasoned chicken to the skillet and cook for 5-7 minutes, stirring occasionally, until the chicken is cooked through and lightly browned. Remove chicken from the skillet and set aside.
In the same skillet, add sliced red bell pepper, green bell pepper, and onion. Sauté for 4-5 minutes until vegetables are tender.
Add minced garlic and cook for an additional 1 minute until fragrant.
Pour in heavy cream and chicken broth, stirring to combine. Bring the mixture to a simmer and cook for 3-4 minutes until the sauce slightly thickens.
Stir in 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 to the skillet and toss gently to combine all ingredients and evenly coat the pasta with the sauce.
Remove from heat and sprinkle chopped fresh parsley over the top before serving.