Start by boiling a pot of water and adding the fettuccine. Cook it al dente, which means it should be tender yet firm to the bite. Check it often to avoid overcooking.
In a large skillet, melt the unsalted butter over medium heat. Add the smoked sausage pieces and brown them until they are sizzling and emit a delightful aroma. Do not overcrowd the pan to ensure they crisp nicely.
Pour in the heavy whipping cream and stir gently. Let it come to a gentle bubble. Add the minced garlic, cajun seasoning, kosher salt, black pepper, and crushed red pepper as it thickens. Use moderate heat to avoid burning the garlic.
Once your sauce is creamy and slightly thickened, add the grated parmesan cheese. Stir well until fully melted and incorporated for a smooth consistency.
Drain the cooked fettuccine and toss it into the creamy sausage mixture. Gently stir until all the pasta is well-coated in the sauce. Avoid stirring too vigorously to prevent breaking the pasta.
Serve your Cajun Alfredo hot and garnish with a sprinkle of fresh parsley for a delightful finish. It is best enjoyed warm.