Butternut squash soufflé makes an excellent side dish for a fall meal

Many people are scared of the word soufflé, which conjures visions of collapsed messes. In truth, soufflés are fairly easy.
This soufflé doesn’t rise to great heights, but that’s OK. It’s still plenty airy, and the flavor is wonderful. It’s simpler than many soufflés because it doesn’t require a roux; but that means that it’s important to drain the cooked squash well, to make your purée as dry as possible. Otherwise the soufflé will be heavy and wet.
I like to roast the squash rather than steam it, mainly because it doesn’t require peeling, but also because, I think, it produces a more concentrated flavor. I simply cut it in half, scoop out the seeds and roast it face down on a lightly oiled baking sheet. I like to rub the surface of the squash with garlic and tuck a few sprigs of thyme under the halves. The purée can be made a day or two in advance.
You can bake the soufflé in a traditional mold, but I actually prefer a shallower dish because I like the golden brown top.
It makes an excellent side dish for a fall meal (Thanksgiving, anyone?), or a main dish for a light supper or lunch.
Serves 4.
1 butternut squash, weighing about 2 pounds (1 kg)
2 cloves garlic, peeled and smashed
a few sprigs of fresh thyme
olive oil for the baking pan
1 teaspoon salt
½ teaspoon freshly ground black pepper
½ teaspoon grated nutmeg
3 oz (85 g) melted butter, plus extra for the baking dish
4 egg yolks, at room temperature
6 egg whites, at room temperature
1. Preheat the oven to 400°F (200°C). Cut the squash in half and use a spoon to scoop out the seeds. Rub the surface of the squash with the garlic and place it face down on a lightly oiled baking sheet, along with the garlic and the thyme. Roast until the squash is soft and starting to collapse, about 25 minutes.
2. As soon as the squash is cool enough to handle, use a spoon to scoop out the flesh. Place the flesh in a fine-mesh strainer (if you don’t have one, use a colander lined with cheese cloth) set over a bowl and gently press the excess liquid out.
3. In a food processor or with an immersion blender, purée the drained squash along with the garlic cloves. Measure out 1½ cups (400 g) and reserve any for another use. (Note: Recipe can be completed a day or two in advance up to this point, but be sure to bring the squash purée to room temperature before continuing.)
4. Preheat the oven to 375°F (190°C). Generously butter a 2-quart soufflé dish or casserole.
5. Transfer the squash to a mixing bowl and season with salt, pepper and nutmeg. Stir in the melted butter and the egg yolks until thoroughly combined.
6. In another bowl (or with a stand mixer), whip the egg whites until they are barely stiff, not dry. Gently fold the whites into the squash mixture. Transfer to the prepared dish and bake for about 30 minutes, until the surface is deep golden brown and firm to the touch. Serve immediately.