1 medium winter squash (about 2 pounds)
1/4 cup chicken broth
1/2 cup finely grated parmesan cheese, plus more for dusting and for garnish
1 tablespoon dried sage
3/4 teaspoon salt
3 egg yolks
3 tablespoons all-purpose flour
3/4 cup whole milk
6 tablespoons unsalted butter
4 egg whites at room temperature
Preheat the oven to 375°F. Put the squash on a cutting board and carefully cut it in half lengthwise with a large chef’s knife or serrated knife. Poke 2 or 3 slits into the squash skin and place the two halves, flesh-side down, on a baking sheet. Roast until tender to the touch, about 30 minutes. Remove from the oven and let cool (see Note).
Scoop out the seeds with a spoon and discard them. Carefully scoop out the cooked flesh. Place half in a blender with the chicken broth and blend until smooth. You should have about 12 cup of purée. Pour the purée into a large bowl; add the cheese, sage, salt, and egg yolks and whisk until smooth. Cut the remaining squash into 1/2-inch chunks and fold them into the puréed mixture. Set aside.
Preheat the oven to 400°F. Lightly butter the sides and bottoms of six 6-ounce (3/4 cup) ceramic ramekins and dust them with grated Parmesan cheese. Arrange the ramekins on a baking sheet and set aside. put the flour in a small bowl and add the milk slowly while whisking. Whisk until completely smooth. Put the butter in a medium saucepan and melt over medium heat. Simmer the butter while stirring constantly, until it looks brown and smells toasty, about 1 minute.
Remove from the heat and whisk the flour-and-milk mixture into the butter. Place the saucepan back on the stove and cook for 30 seconds. Pour into the squash mixture and whisk together.
Pour the egg whites into the bowl of an electric mixer fitted with the whip attachment. Whip at medium speed until the egg whites form shiny, medium peaks that hold their shape. Stir half of the whites into the squash base to lighten it.
Fold in the remaining whites and spoon the soufflé mixture evenly among the buttered ramekins. Sprinkle each soufflé with grated Parmesan cheese. immediately place the soufflés into the oven and bake until they are just set in the center and golden on top, 15 to 20 minutes. To test for doneness, use a paring knife to pry the top of a soufflé open just enough to look inside; it should appear softly set. Serve immediately after removing from the oven.
Roast your squash 1 or 2 days beforehand, if you like. Wrap and store in the refrigerator until you are ready to assemble and bake the soufflés.
Excerpted from Savory Baking: Warm and Inspiring Recipes for Crisp, Crumbly and Flaky Pastries. Published by Chronicle Books. Copyright © 2009 by Mary Cech. All rights reserved. Reprinted by permission of Chronicle Books.