Preheat your oven to 375°F (190°C).
In a large pot, bring salted water to a boil. Add the pasta and cook according to package instructions until al dente. In the last 2-3 minutes of cooking, add the broccoli florets to the boiling water with the pasta. Drain and set aside.
In a large saucepan, melt the butter over medium heat. Add the minced garlic and sauté for about 1-2 minutes until fragrant. Sprinkle the flour over the garlic and butter mixture, stirring constantly to create a roux. Cook for 1-2 minutes until the mixture turns a light golden color. Gradually whisk in the heavy cream, ensuring no lumps form. Add the grated Parmesan cheese, salt, pepper, and nutmeg (if using). Continue to whisk until the sauce thickens, about 5-7 minutes.
In a large mixing bowl, combine the cooked pasta and broccoli, the shredded chicken, and the Alfredo sauce. Mix well to ensure everything is evenly coated with the creamy sauce.
Pour the mixture into a greased 9×13 inch baking dish. Spread it out evenly.
Sprinkle the shredded mozzarella cheese evenly over the top of the pasta mixture.
Place the baking dish in the preheated oven and bake for 25-30 minutes, or until the top is golden and bubbly.
Once baked, remove from the oven and let it sit for a few minutes. Garnish with fresh parsley if desired. Serve hot and enjoy!
