Ingredients: Topping: 4 slices white sandwich bread, torn into quarters (other bread fine too) 2 tablespoons butter, melted Filling: 3 pounds russet potatoes (about 4-5 medium), peeled and sliced 1/8 inch thick 1 ½ teaspoons salt 4 tablespoons butter 1 medium onion, chopped 1 teaspoon dried thyme 3 medium garlic cloves, finely minced 6 tablespoons all-purpose flour 2 cups low-sodium chicken broth 3/4 cup heavy cream or milk 6 ounces Swiss cheese, shredded, about 2 cups 2 tablespoons Dijon mustard 1/4 teaspoon cayenne pepper 2 pounds boneless, skinless chicken breasts, trimmed of excess fat and sliced thinly 9 ounces deli ham, chopped 2 tablespoons minced fresh parsley leaves
Instructions: For the topping, process the bread and butter in a food processor until coarsely ground. Set aside. Preheat oven to 400 degrees for baking, making sure the oven rack is in the middle position. Place the potatoes, 6 cups water and 1 teaspoon salt in a large pot. Bring to a boil over high heat, then reduce the heat to a simmer and cook, uncovered, until the potatoes are partially cooked, about 2 minutes (don’t overcook because they will continue to cook in the oven!). Carefully drain potatoes, or remove them with a slotted spoon, and transfer them to a bowl. Set aside. For the sauce, melt the butter in a medium saucepan over medium heat. Add the onion, thyme, and 1/2 teaspoon salt. Cook until the onions are softened, about 6 minutes. Add the garlic and cook until fragrant, stirring constantly, about 1 minute. Add the flour and cook, stirring constantly, until golden, about 1 minute (this helps cook out the flour taste in the roux). Slowly whisk in the chicken broth and the cream or milk. Bring the mixture to a simmer, whisking often, until slightly thickened (if using milk instead of cream, you may have to cook longer for it to thicken up a bit). Off the heat, whisk in the Swiss cheese, Dijon, and cayenne pepper until smooth. Season with salt and pepper to taste. Cover and set aside until ready to use. Toss the potatoes with half of the sauce and spread into the bottom of a lightly greased 9X13 inch baking pan. Layer alternating pieces of the chicken and ham over the potatoes, overlapping as needed. This is not a scientific procedure, just make sure that the chicken is in a single layer (not on top of each other) so that it cooks thoroughly. Pour the remaining sauce evenly over the chicken and sprinkle with the bread crumb topping. Bake until the chicken is cooked through and the casserole is bubbling, 30 to 35 minutes (add about 5-7 additional minutes onto the baking time if baking it after it has chilled in the refrigerator for more than a couple of hours). Sprinkle with parsley and cool for 10 minutes before serving.