Begin by boiling a large pot of salted water over high heat. Once boiling, add linguine or fettuccine and cook according to package instructions until al dente, usually around 8-10 minutes. Stir occasionally to prevent sticking, then drain the pasta in a colander and set aside.

In a spacious skillet, warm 2 tablespoons of olive oil over medium heat. Add the diced onion, red bell pepper, and green bell pepper, and sauté for about 5 minutes until they become tender and fragrant.

Stir in 1 pound of sliced andouille sausage along with 3 minced garlic cloves to the skillet. Cook for an additional 3 to 4 minutes, stirring frequently until the sausage is browned and fragrant.

Next, introduce 1 pound of peeled and deveined shrimp to the skillet. Cook for about 3 to 4 minutes until the shrimp turn pink and opaque.

Pour in 1 can of diced tomatoes and 1 cup of heavy cream into the skillet, stirring well. Sprinkle in 1 teaspoon of Cajun seasoning along with salt and pepper to taste. Let the mixture simmer for 5 to 7 minutes until the sauce slightly thickens.

Add the cooked pasta directly into the skillet with the sauce, gently tossing everything together to ensure the pasta is thoroughly coated. Continue to heat for an additional 2 to 3 minutes.

Remove the skillet from heat and stir in ¼ cup of chopped fresh parsley and ¼ cup of grated Parmesan cheese. Serve immediately, garnished with extra parsley or cheese as desired.