In this video, you’ll see how to turn chicken cordon bleu into a tasty, easy-to-make, open-faced sandwich. You’ll start by sautéing diced smoked ham and onions in butter. Then you’ll make a quick roux, leading to a thick, simple béchamel sauce flavored with Gruyere cheese and Dijon mustard. Last but not least, you’ll add diced leftover chicken and a secret ingredient, dill pickles. Spoon the chicken mixture over sliced French bread and top it off with a little extra shredded Gruyere. They’ll bake open-faced in the oven until the cheesy tops are beautifully golden brown. Watch the video, then get Chef John’s recipe for Chicken Cordon Bleu Sandwiches. This is an incredibly delicious way to use up leftover chicken.