Heat a large, heavy-bottomed pot over medium-high heat. Add the sliced andouille sausage (no oil needed) and cook for 4–5 minutes, stirring occasionally, until browned.
Push the sausage to the side and add the cubed chicken thighs to the rendered fat. Cook for 5–6 minutes, stirring occasionally, until browned on the outside.
Add the diced onion, bell pepper, and celery to the pot. Cook for 5–7 minutes, stirring often, until softened. Add the garlic in the last minute.
Sprinkle in the Cajun seasoning, smoked paprika, and cayenne (if using). Stir constantly for 30–60 seconds until fragrant.
Pour in the chicken broth, Worcestershire sauce, and Kitchen Bouquet (if using), scraping the bottom of the pot. Bring to a rolling boil and taste the broth, adjusting salt and seasoning as needed.
Stir in the dry pasta. Reduce heat to a gentle simmer, cover, and cook for 12–15 minutes, stirring every 3–4 minutes, until the pasta is tender and the sauce has thickened and clings to the noodles.
Remove from heat and let rest, covered, for 5 minutes. Stir in the green onions and parsley before serving.