Cook the fettuccine pasta according to the package instructions until al dente.
While the pasta cooks, heat olive oil in a large skillet over medium heat.
Add the chopped onion and bell pepper; sauté until softened, about 5 minutes.
Stir in the minced garlic and cook for about 30 seconds until fragrant.
Add the shrimp and Cajun seasoning; cook until the shrimp turn pink, about 3-4 minutes.
Pour in the heavy cream and chicken broth, stirring to combine.
Simmer for 5-7 minutes, allowing the sauce to thicken slightly.
Toss the cooked fettuccine into the sauce, mixing until well coated.
Season with salt and pepper to taste, and garnish with fresh parsley before serving.