Boil the pasta in salted water according to the package instructions.
Drain and set aside, reserving ½ cup of the pasta water for the sauce.
2. Prepare the Proteins
Heat olive oil and butter in a large skillet over medium heat.
Add the sliced sausage and cook until browned on both sides. Remove and set aside.
In the same skillet, add the shrimp. Sprinkle with a pinch of Cajun seasoning and cook for 2–3 minutes per side until pink and fully cooked. Remove and set aside.
3. Make the Cajun Sauce
Lower the heat to medium-low and add garlic to the skillet. Sauté for 30 seconds until fragrant.
Stir in the tomato paste (if using) and smoked paprika, letting them blend with the garlic.
Pour in the chicken or seafood stock, scraping the bottom of the skillet to deglaze.
Add the heavy cream and bring to a gentle simmer.
Stir in Parmesan cheese until melted, then add Cajun seasoning, onion powder, salt, and pepper to taste.
4. Combine Everything
Return the sausage and shrimp to the skillet, letting them simmer briefly in the sauce.
Add the cooked pasta, tossing to coat evenly. If the sauce is too thick, stir in the reserved pasta water a little at a time.
5. Serve and Garnish
Plate the pasta and sprinkle with chopped parsley and extra Parmesan cheese, if desired.
