Turkey and Cheese Soufflé Casserole
1 baguette, cut into ¾-inch slices
Leftover turkey, cut into pieces about ½-inch thick (let the turkey warm up a bit from refrigerator temperature)
4 tablespoons softened butter
One large onion, peeled and cut in half through the poles, then each half sliced thinly.
You’ll need a 13 x 9-inch glass or ceramic baking dish. Turn the oven on to 350 degrees F. Arrange the bread slices in the bottom of the pan to see how many you’ll need. You’ll want to cover the entire bottom of the dish. Then put those slices on a baking sheet and put them in the oven for about 10 minutes (it’s fine while the oven is preheating) to get the bread lightly golden. Take the bread slices out and let them cool a few minutes. Spread a tablespoon of the softened butter in the bottom of the baking dish. Then arrange the cooled bread slices on top of the butter and spread 2 tablespoons of soft butter on top of the bread slices. Cover the bread slices with the sliced turkey. Use the remaining tablespoon of butter to sauté the onion until lightly browned, adding some salt and pepper to as it cooks. Spread the onion on top of the turkey. Put the baking dish on the baking sheet and set it aside.
(Note – if you have leftover creamed onions, you can roughly chop some to spread on the turkey instead of using the whole onion)
3 tablespoons butter
4 tablespoons flour
¼ teaspoon dry mustard powder
¼ teaspoon salt
¼ teaspoon cayenne pepper
Freshly ground black pepper
1-1/2 cups cold milk
6 large eggs, separated
8 ounces sharp cheddar cheese, grated (preferably not colored orange, it just looks better)
Melt the butter in a saucepan over medium heat. Add the flour, mustard powder, salt, cayenne, and some black pepper and whisk together. Cook for about 30 seconds to a minute, whisking to keep the mixture from burning. Keep whisking while you pour in the milk, then raise the heat and whisk and cook until the mixture thickens.
Turn the heat to medium and add all six egg yolks to the thickened sauce, whisking them constantly. Cook for another minute and remove the pan from the heat.
Put the egg whites in a large, very clean bowl and beat with an electric mixer. Start on low speed, until the whites start to foam. Then add a big pinch of salt and raise the speed to high. Beat until the whites form soft peaks – when you lift the mixture, the peaks formed flop back over. Then beat some more but watch carefully. You want to beat the whites just to the point where the peaks stand up when you lift the mixer; if you go beyond this point the whites might get dry and grainy. (If this happens, add another egg white and beat the mixture a little more to get the right consistency).
Scoop about a quarter of the egg whites into the egg mixture in the saucepan and stir the whites in with a whisk. Then switch to a rubber spatula. Pour the mixture in the saucepan over the egg whites and fold everything together. Plunge the spatula into the center of the bowl, bring it along the bottom and up the side, then back over the middle. Rotate the bowl a little and repeat. It should take 30 seconds to a minute to get everything just about mixed, there should still be some visible egg whites. Then sprinkle about ¾ of the grated cheddar cheese on and gently fold it in, everything should now be mixed and light.
Pour the soufflé over the bread and turkey, then smooth the top with the spatula. Sprinkle with the remaining cheddar cheese. Put the dish (still on the baking sheet) into the oven and bake for 30 minutes or so, until the soufflé has puffed and top is a nice golden brown. Serve it right away, using a large spoon to get under the bread slices.