Serves: Makes 8 servings
- 11⁄4 cups (4 ounces) sliced mushrooms
- 1 tablespoon unsalted butter
- 1 shallot, very finely chopped
- 1 teaspoon minced fresh thyme
Béchamel and Egg Whites:
- 1⁄2 stick (2 ounces) unsalted butter, cut into pieces
- 1⁄4 cup (1⁄4 ounce) unbleached all-purpose flour
- 1 cup (8 ounces) whole milk
- 3⁄4 cup (3 ounces) grated fontina cheese
- 1⁄4 cup (1 ounce) grated Parmesan cheese
- 1⁄2 teaspoon salt
- 4 grinds black pepper
- Pinch of cayenne (optional)
- 4 large eggs, separated, plus
- 1 additional egg white
- 1⁄4 teaspoon cream of tartar
- Preheat the oven to 400°F and position an oven rack in the bottom third. Generously butter the soufflé dishes (including the rims), coat them with fine, dry bread crumbs or finely grated Parmesan cheese, and tap out the excess.
- Cook the mushrooms: Process the mushrooms in the bowl of the food processor until very finely chopped, 20 to 30 seconds. Melt the butter in the medium sauté; pan over high heat until hot and bubbling. Add the shallot and cook until translucent, about 1 minute. Add the mushrooms and cook until they have given up their liquid, it has evaporated, and the mushrooms look dry, about 5 to 6 minutes. Stir in the thyme and set aside.
- Make the béchamel: Melt the butter in the small saucepan over medium heat. Remove from the heat, add the flour, and whisk well to remove any lumps. Return to the heat and cook for 1 minute, whisking constantly. Remove from the heat and add the milk slowly, whisking constantly to remove any lumps. Return to the heat and bring to a boil, whisking constantly. Boil for 1 to 2 minutes, whisking, until thickened to the consistency of thin pudding. Transfer the mixture to the large bowl and whisk in the mushroom mixture, fontina, Parmesan, salt, pepper, and cayenne. Whisk in the egg yolks and set aside.
- Whip the egg whites: In the very clean bowl of the stand mixer, whip the 5 egg whites and the cream of tartar on medium speed until they form firm peaks. You can also use a hand mixer and a medium bowl. Be careful not to overbeat. With the spatula, gently stir one-fourth of the egg whites into the béchamel to lighten the mixture. Fold in the remaining whites just until there are no more streaks of whites.
- Fill the dishes and bake: Transfer the soufflé batter to the pastry bag. Pipe the batter into the prepared soufflé dishes, filling each one to 1⁄4 inch below the rim. Set the dishes on the baking sheet. Bake for 13 to 16 minutes, until the soufflés are set and firm to the touch in the center. Serve immediately.