Preheat the broiler. Place the bread on a cookie sheet and broil until a light brown. Turn the bread over and broil the other side until light brown as well. Remove the bread and set aside.
In a medium sauce pan, melt the butter over medium heat. When the butter is completely melted, whisk in flour. Continue to whisk until the mixture turns a light tan (approximately 2 minutes). Add the warm milk one cup at a time and whisk after each addition. Cook for 2 minutes. Whisk in 6 tablespoons of the parmesan cheese, egg, and MUSTARD GIRL AMERICAN DIJON MUSTARD. Season with salt and pepper. Cook the mixture for 5 minutes, stirring constantly and being careful not to let the mixture boil. Remove from heat.
Preheat the broiler once again. Place a slice of bread in each of four oven safe plates or large bowls. Top each piece of bread with a slice of tomato and a liberal amount of turkey. Ladle a generous amount of sauce over the top of the turkey, covering the bread and toppings. Sprinkle with the remaining parmesan. Place the dish under the broiler until the top is lightly browned and bubbly. Remove from the broiler, place two pieces of bacon crossed over the top, and serve immediately.