Step 1: Cook the Pasta

1. Bring a large pot of salted water to a boil. Cook the pasta according to package instructions until al dente. Reserve 1 cup of pasta water, then drain and set aside.

Step 2: Cook the Shrimp and Sausage

1. Heat olive oil in a large skillet over medium-high heat.
2. Season the shrimp with 2 teaspoons of Cajun seasoning and add them to the skillet. Cook for 2–3 minutes per side, or until pink and opaque. Remove and set aside.
3. In the same skillet, cook the sliced sausage for 3–4 minutes until browned. Remove and set aside with the shrimp.

Step 3: Sauté the Aromatics

1. Reduce the heat to medium and melt the butter in the skillet. Add the diced onion, minced garlic, and sliced bell pepper. Cook for 4–5 minutes, stirring occasionally, until softened and fragrant.

Step 4: Make the Sauce

1. Stir in the Cajun seasoning, smoked paprika, and red pepper flakes (if using). Cook for 1 minute to toast the spices.
2. Pour in the heavy cream and chicken broth, stirring to combine. Bring the mixture to a gentle simmer.
3. Stir in the grated Parmesan cheese and let the sauce thicken slightly, about 2–3 minutes. Adjust the seasoning with salt and pepper.

Step 5: Combine and Serve

1. Return the cooked pasta, shrimp, and sausage to the skillet. Toss everything together to coat evenly in the sauce. If the sauce is too thick, add reserved pasta water, a few tablespoons at a time, until desired consistency is reached.
2. Serve the pasta in bowls or on plates, garnished with fresh parsley and additional Parmesan cheese.