Preheat the Oven: Set your oven to 375°F (190°C). Lightly grease a 9×13-inch casserole dish with non-stick spray to ensure easy cleanup and prevent sticking.
Prepare the Filling: In a large mixing bowl, combine the cooked and shredded chicken with the Alfredo sauce and chicken broth. Stir to combine until the mixture is evenly blended and smooth. This creamy base helps bind everything together in the casserole.
Add the Main Ingredients: To the same bowl, add the frozen cheese tortellini (no need to thaw), the drained quartered artichoke hearts, fresh baby spinach, shredded mozzarella cheese, and ½ cup of the Parmesan cheese. Stir thoroughly to ensure everything is evenly coated with the sauce and the mix is well combined. The spinach will wilt as it bakes, so no need to pre-cook it.
Transfer to Dish: Pour the entire mixture into the prepared casserole dish, spreading it out evenly with a spatula or the back of a spoon. Cover the dish loosely with aluminum foil—this traps steam to help melt the cheese and cook the tortellini evenly.
Bake: Place the dish in the preheated oven and bake for 40 minutes. At this stage, the tortellini should be tender, and the casserole should be bubbling gently around the edges.
Top and Bake Again: Remove the foil and sprinkle the remaining ½ cup of Parmesan cheese evenly over the top of the casserole. Return the dish to the oven uncovered, and bake for an additional 10 to 15 minutes. The cheese on top should be melted, golden brown, and slightly crispy at the edges.
Cool and Serve: Remove the casserole from the oven and let it cool for 5–10 minutes. This resting period allows the sauce to thicken slightly and makes serving easier. Garnish with chopped fresh parsley or a sprinkle of black pepper for an extra pop of color and flavor.
