1-First Step: Gather all your ingredients and tools to streamline the process. Preheat your oven to 350 degrees Fahrenheit and lightly spray a 9×13 casserole dish with cooking spray. This sets the stage for a smooth assembly, allowing you to focus on layering without interruptions.

2-Second Step: Prepare the main layers by shredding your rotisserie chicken if it isn’t already. Shred 5 1/2 cups of chicken and cube 2 cups of ham, then layer the shredded chicken evenly at the bottom of the casserole dish. This base ensures the dish holds together well and infuses flavor throughout.

3-Third Step: Start the cheese sauce by melting 4 tablespoons of butter in a saucepan over medium heat. Once melted, sprinkle in 1/4 cup of all-purpose flour and cook for 1 to 2 minutes, stirring until it becomes dry and clumpy. This roux is the foundation for a thick, creamy sauce that ties the chicken cordon bleu casserole together.

4-Fourth Step: Slowly whisk in 2 cups of milk, making sure to use at least 2% for the best consistency. Add 1 tablespoon of Dijon mustard, 1 tablespoon of lemon juice, 1/2 teaspoon of garlic powder, and 1/4 teaspoon of salt. Simmer for 3 to 5 minutes, whisking constantly until the sauce thickens nicely.

5-Fifth Step: Remove the saucepan from heat and stir in 1 1/4 cups of shredded Swiss cheese, along with optional Parmesan cheese. Pour this cheese sauce evenly over the chicken and ham layers in the dish. For adaptations, if you’re making a gluten-free version, swap the flour here with cornstarch as noted in tips.

6-Sixth Step: In a small bowl, mix 1 cup of Panko bread crumbs with 2 tablespoons of melted butter until well combined. Sprinkle this mixture evenly over the top of the casserole for that irresistible crunch.

7-Seventh Step: Bake the casserole uncovered for 30 to 35 minutes, or until the topping turns golden brown and the dish is bubbly. Let it cool for 5 to 10 minutes before serving to allow the flavors to settle.

8-Final Step: Serve your chicken cordon bleu casserole with sides like pasta or broccoli for a complete meal. This simple chicken cordon bleu casserole not only satisfies hunger but also offers flexibility for dietary preferences, such as using low-carb alternatives. If you enjoy easy chicken dishes, try our easy chicken spaghetti recipe for another quick option.