Preheat your oven to 190 °C (375 °F). In a large mixing bowl, combine the cubed chicken, cooked pasta or cauliflower rice, and broccoli florets. Season with salt, pepper, and Italian seasoning. Toss gently to distribute the seasoning evenly. This creates the hearty base of your bake and ensures each bite is properly seasoned.

In a medium saucepan over low heat, melt the cream cheese with Greek yogurt and minced garlic, stirring until smooth and creamy. Slowly pour in the chicken broth and continue to whisk until the sauce loosens. Stir in half of the Parmesan and half of the mozzarella cheese, mixing until fully melted and silky. This rich Alfredo sauce is the star of the casserole.

Pour the creamy Alfredo sauce over the chicken, broccoli, and pasta mixture. Stir gently until everything is coated in the sauce. Transfer the mixture to a greased casserole dish and spread it into an even layer. The sauce should cling to every bit, ensuring flavor in every portion.

Sprinkle the remaining Parmesan and mozzarella evenly over the top. Bake in the preheated oven for 20–25 minutes or until the top is golden and bubbly. Allow the casserole to sit for 5 minutes before serving so it sets and becomes easier to portion.