Cook pasta according to package instructions. Reserve 1 cup pasta water.
In a large skillet, brown sliced andouille sausage over medium-high heat for about 5 minutes. Remove and set aside.
In the same pan, add olive oil and sauté mushrooms until golden, about 5-7 minutes.
Add butter and garlic, cooking for 1 minute until fragrant.
Add bell peppers and cook for 3 minutes until slightly softened.
Stir in Cajun seasoning, then add heavy cream and chicken broth. Bring to a simmer and cook until the sauce starts to thicken, about 5 minutes.
Add Parmesan cheese and stir until melted and smooth.
Return sausage to the pan and add cooked pasta, tossing to coat.
Adjust the consistency with reserved pasta water if needed.
Garnish with parsley and extra Parmesan.