This Chicken Cordon Bleu Casserole is simple and delicious. It combines tender chicken and smokey, flavorful ham in a melty, creamy cheese sauce topped with crispy breadcrumbs. Your whole family will love it!
Preheat the oven to 350 degrees Fahrenheit and spray a 3-quart baking dish with pan spray.
Spread the shredded 5 cups rotisserie chicken in the bottom of the pan. Sprinkle the chopped 8 ounces deli ham, evenly over the chicken.
In a small bowl, stir together 2 tablespoons unsalted butter, melted, 1 ½ cups panko bread crumbs, 1 teaspoon Italian seasoning, and ½ teaspoon salt. Set aside.
Prepare the lemon cream sauce by melting 6 tablespoons unsalted butter in a medium saucepan over medium heat. Once melted, add 4 tablespoons all-purpose flour and whisk to combine. Continue to whisk until the mixture becomes nutty and fragrant and the bubbling subsides. About 2 minutes.
Slowly whisk in 1 cup chicken broth, ⅔ cup heavy cream, 1 ⅓ cup milk, and 1 tablespoon dijon mustard. Whisk until smooth and thickened, about 3-4 minutes. Whisk in the ½ cup parmesan cheese,½ cup swiss cheese, slowly, whisking until it is fully melted. Whisk in ⅓ cup fresh lemon juice and salt and pepper, to taste.
Pour the sauce evenly over the chicken and ham and top with the shredded 1 cup swiss cheese,. Top with the panko mixture and bake for 30-35 minutes, until the casserole is bubbling and the bread crumbs are golden brown. Top with chopped parsley and hollandaise, if desired.