Very few dishes inspire "oohs" and "ahs" like a hot soufflé; served right out of the oven. Despite its relative simplicity, many cooks shy away from the very thought of attempting a soufflé; because it's perceived to be so tricky. Actually, the components of a soufflé; can be assembled ahead of time, so it's really only the cooking stage that takes last-minute attention. If you time the soufflé to be the last item to the table, you can't go wrong! Many vegetables lend themselves to a savory soufflé, but broccoli is especially flavorful. Although this recipe calls for nutty Gruyere or Conte cheese, you can substitute other favorite varieties with equal success. Bon appétit!
Position a rack in the lower third of the oven, place a rimmed baking sheet on the rack, and preheat to 400 degrees F. Butter the bottom and sides of a 6-cup soufflé dish, then sprinkle with the Parmesan cheese to coat the bottom and sides. Set aside.
Melt the butter in a medium-size saucepan over medium heat and stir in the flour, cayenne, and nutmeg to make a roux. Cook the roux, stirring constantly, for 2 to 3 minutes to cook the flour. Add the milk and whisk to blend. Continue cooking until the sauce is thick, stirring frequently. Remove the pan from the heat and whisk in one egg yolk; when it’s incorporated, add the remaining yolks one at a time, stirring constantly. Add the cheese, salt, and broccoli to the saucepan and stir to blend. This is your soufflé base; set it aside to cool for 10 minutes.
Meanwhile, beat the egg whites until stiff. Gently stir about one third of the whites into the broccoli base to loosen the mixture. Then, carefully fold in the remaining whites, taking care not to deflate the mixture. Transfer to the prepared dish and place on the rimmed baking sheet.
Bake the soufflé for 15 minutes, then reduce the oven temperature to 375 degrees F. Bake until the soufflé has risen above the rim of the pan and is puffed and golden brown, 10 to 15 minutes more. Remove from the oven and serve immediately. If the soufflé falls before you serve it, don’t worry — it will still taste delicious!