Creating Creamy Chicken Alfredo Casserole is straightforward with these clear steps:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C).
2. Cook the Pasta: In a large pot of boiling salted water, cook the rotini pasta according to package instructions until al dente. Drain and set aside.
3. Sauté Garlic: In a large skillet, heat the olive oil over medium heat. Add the minced garlic and sauté until fragrant, about 1 minute.
4. Make the Sauce: In the same skillet, pour in the heavy cream and chicken broth. Stir in the grated Parmesan cheese and Italian seasoning. Let the sauce simmer for about 3-5 minutes.
5. Mix Chicken and Pasta: Add the shredded chicken and cooked pasta to the skillet. Stir everything together until fully coated with sauce.
6. Season: Season the mixture with salt and pepper to taste.
7. Transfer to Baking Dish: Pour the chicken and pasta combination into a greased 9×13 inch baking dish.
8. Add Mozzarella: Top with shredded mozzarella cheese evenly over the casserole.
9. Bake: Place the baking dish in the oven and bake for 25-30 minutes, or until the cheese is bubbly and golden.
10. Garnish and Serve: Once baked, remove from the oven and let it cool slightly. Garnish with chopped parsley before serving.

Following these steps will ensure your casserole turns out perfectly creamy and delicious, bringing rave reviews from all who try it!