1- In a large pot or Dutch oven, melt 2 Tbsp butter over medium heat. Add the diced onion, chicken pieces, a pinch of salt, and pepper; sauté until the chicken begins to brown.

2- Push the mixture to one side, add the remaining 2 Tbsp butter, then stir in the green onions, thyme, paprika, garlic powder, and cayenne. Cook for 2 3 minutes until fragrant and lightly golden.

3- Pour in the broth and milk, stirring to combine. Bring the liquid to a gentle boil.

4- Add the rotini, zucchini, and season with additional salt and pepper. Reduce the heat and simmer, uncovered, for about 8 minutes, or until the pasta is al dente and most of the liquid has been absorbed.

5- Remove the pot from the heat. Stir in the Parmesan and 1 cup (≈ 115 g) of the shredded cheddar (or cheese blend) until melted and evenly distributed.

6- If desired, transfer the mixture to an oven-safe baking dish. Sprinkle the remaining shredded cheese over the top.

7- Bake for 20 minutes, or until the cheese is fully melted, bubbly, and lightly browned.

8- Garnish with fresh thyme leaves (and optional fresh basil) before serving.