"Why this recipe works:These open-faced sandwiches are made from toasted white bread topped with sliced chicken or turkey, smoky ham or bacon, and a rich, cheesy white sauce. Vegetables often show up in this hefty sandwich as well, and we opted for tomato and sautéed mushrooms in our version. After it’s assembled, the whole thing is passed under a broiler until it’s golden brown and bubbly. We used sturdy, thick-cut bread to stand up to all the toppings and made the sauce extra thick so it stayed put under the broiler...."