Cheese Soufflé

1. Grease a 2-quart or other deep baking dish with butter. Put 4 tablespoons butter in a medium saucepan over medium-low heat. When the foam subsides, stir in the flour and cook, stirring, until the mixture darkens, about 3 minutes.
2. Turn the heat to low and whisk in the milk, a bit at a time, until the mixture is thick. Let cool for a few minutes, then beat in the egg yolks, sprinkle with salt and pepper, cayenne or mustard, and the cheeses.
3. When you are ready to bake the soufflé, heat the oven to 375°F. Use a stand or hand-held mixer to beat egg whites until stiff peaks. Fold in about a third of the egg whites into the base. Use a rubber spatula to scoop the mixture from the bottom and fold it over the top; don‘t worry about deflating the whites too much at this point. Add the rest of the egg whites, using the same folding technique, but more gently. Incorporate the whites well into the base, but if light streaks remain, that’s OK. If the batter goes flat, it’s overmixed, and your soufflé won’t rise much; the results will be more like a puffy quiche, so not a total disaster.
4. Transfer the batter to the prepared baking dish. Bake until the top is brown, the sides are firm, and the center is still quite moist, about 30 minutes. Use a thin skewer to check the interior; if it comes out quite wet, bake for another 5 minutes. If it is just a bit moist, the soufflé is done. Serve right away, spooned directly from the baking dish.

— Recipe from How to Cook Everything: Completely Revised Twentieth Anniversary Edition