Cook the fettuccine according to package instructions until al dente.
In a large skillet, heat olive oil over medium heat and add diced onion.
Add minced garlic and sliced smoked sausage to the skillet; sauté until the sausage is browned.
Stir in bell peppers and Cajun seasoning; cook for an additional 3-4 minutes.
Pour in chicken broth and bring the mixture to a simmer.
Slowly whisk in heavy cream until well combined.
Add cooked fettuccine to the sauce, tossing to combine.
Season with salt and black pepper to taste, adjusting flavors as needed.
Serve hot, garnished with freshly grated Parmesan cheese.
