Boil the pasta in a pot of salted water, following the instructions on the package. Once cooked, drain and set aside.
Melt 3 tablespoons of butter in a large skillet.
Start seasoning the shrimp with Cajun spice and smoked paprika and cook in butter until they reach a pleasing pink hue. Once cooked, use a spoon to carefully remove them from the skillet and place them aside.
Now, add the remaining butter to your skillet. Once it is melted, throw in onions, bell peppers, tomatoes, mushrooms, and sausage for a savory combination of flavors. Stir-fry until each vegetable is cooked to tender perfection and the sausage has browned nicely.
Add and sauté the tomato and garlic for 1 1/2 minutes until you get fragrant. Slowly pour in the heavy cream, stirring constantly until it reaches a thickened consistency.
Incorporate the Parmesan, lemon juice, and parsley by stirring it until everything is combined. Don’t forget to taste the dish and adjust its seasoning according to your desired flavor. Add a pinch of salt and pepper for a punchy, delicious finish!
Remove the pan from the heat and add the fettuccine and shrimp. Gently mix everything together.