Make sauce: Melt butter in a saucepan over medium heat. Whisk in flour; cook and stir until it begins to brown slightly. Gradually whisk in milk so that no lumps form; bring to a boil, stirring constantly. Mix in Parmesan cheese and stir in beaten egg to thicken; remove from heat and stir in cream.

Preheat the oven's broiler.

Make sandwiches: For each hot brown, place two slices toast into the bottom of an individual-sized casserole dish. Cover with a liberal amount of roasted turkey and tomato slices. Season with salt and pepper; spoon sauce over top of each one and sprinkle with Parmesan cheese.

Place the dishes under the preheated broiler and cook until speckled brown on top, about 5 minutes. Remove and arrange two slices bacon in a cross shape on top of each sandwich.