1-First Step: Preheat your oven to 350 degrees Fahrenheit. Spray a 9×13 casserole dish with cooking spray so the Chicken Cordon Bleu Casserole releases easily.

2-Second Step: Layer the shredded cooked chicken evenly on the bottom of the dish. For best results, shred chicken finely so each forkful has a bit of everything.

3-Third Step: Layer the cubed ham evenly over the chicken.

4-Fourth Step: Make the cheese sauce. Melt 4 tablespoons butter in a saucepan over medium heat. Sprinkle in 1/4 cup flour and cook for 1 to 2 minutes until dry and clumpy.

5-Fifth Step: Whisk in 2 cups milk slowly to avoid lumps. Add 1 tablespoon Dijon mustard, 1 tablespoon lemon juice, 1/2 teaspoon garlic powder, and 1/4 teaspoon salt. Simmer for 3 to 5 minutes, whisking constantly until thickened.

6-Sixth Step: Turn off the heat and stir in 1 1/4 cups shredded Swiss cheese and Parmesan cheese (for sauce and topping). Taste and adjust salt if needed. Tip: If you want a low-carb version, use cornstarch or xanthan gum in place of flour.

7-Seventh Step: Pour the cheese sauce evenly over the ham and chicken layers. This helps keep the casserole creamy all the way through.

8-Eighth Step: Mix 1 cup Panko bread crumbs with 2 tablespoons melted butter in a small bowl. Sprinkle evenly over the top for a crisp, buttery layer.

9-Ninth Step: Bake uncovered for 30 to 35 minutes until the breadcrumbs are golden brown and the casserole is bubbly.

10-Final Step: Let cool for 5 to 10 minutes before serving. This brief rest helps the Chicken Cordon Bleu Casserole set so portions stay neat.