In a small bowl, whisk together garlic powder, Italian seasoning, paprika, cayenne pepper, onion powder, dried thyme, and salt and pepper to taste (I like 1/2 teaspoon salt and 1/4 teaspoon pepper). Set aside.
To make the pasta:
In a large skillet over medium-high heat, heat oil until shimmering. Add onion, peppers, and celery and cook until softened. Add Andouille sausage and cook until browned.
Stir in garlic until fragrant, about 30 seconds. Add chicken and Cajun seasoning and cook, stirring often, until chicken is browned and cooked through.
Stir in pasta, diced tomatoes and juice, and chicken broth. Simmer uncovered until pasta is al dente and almost all of the liquid is absorbed, about 20 minutes.
Stir in heavy cream and cheddar cheese until melted. Season to taste with salt and pepper. Garnish with Parmesan cheese and fresh parsley if desired.
Kielbasa can be substituted for the Andouille sausage.