Bring a large pot of salted water to a boil. Add the pasta and cook it to al dente according to the package directions. When it's done, remove a cup of the pasta water and set aside. Drain the pasta but do not rinse it.
12-16 ounces short cut pasta (like penne)
While it's cooking, heat the olive oil in a large skillet, like a 10-inch cast iron skillet, over medium-high heat. Add the sausage and 2 teaspoons of cajun seasoning and cook to crisp on both sides, about 5 minutes. Transfer to a clean plate or bowl.
2 Tablespoons olive oil, 1 (12 oz) package smoked andouille sausage, 1 Tablespoon cajun seasoning
Turn the stove down to medium heat and add the onion and pepper, the remaining teaspoon of cajun seasoning, and a little bit of red pepper flakes to the same skillet and cook to soften, about 3 minutes. Add the garlic and cook for another minute, until fragrant.
1 medium yellow onion, 2 bell peppers, Pinch red pepper flakes, 2 cloves garlic
Whisk in the chicken broth, heavy cream, and tomato paste until smooth. Bring the mixture to a gentle boil over medium-high heat then reduce the heat to medium-low and simmer for 5-7 minutes to thicken slightly.
1 1/4 cups chicken broth, 1/2 cup heavy cream, 2 Tablespoons tomato paste
Stir in the parmesan cheese then add the cooked pasta and crispy sausage and toss to coat in the sauce. Add up to 1 cup of the reserved pasta cooking water too thin the sauce slightly as needed. Serve right away with more parmesan cheese and freshly chopped parsley.
1/2 cup grated parmesan cheese