Serves: Makes 6 servings
- 6 tablespoons unsalted butter, plus more for the baking dish
- 1⁄4 cup plus 5 tablespoons freshly grated Parmigiano
- Reggiano cheese
- About 2 pounds green garlic, enough to yield 4 cups sliced
- Kosher or sea salt and freshly ground black pepper
- 3 tablespoons unbleached all-purpose flour
- 1 cup whole milk
- 4 thyme sprigs
- 1⁄4 teaspoon freshly grated nutmeg
- 4 large egg yolks
- 5 large egg whites
- Preheat the oven to 425°F. Generously butter the bottom and sides of a 13 by 9-inch oval gratin dish. Sprinkle the buttered dish evenly with 3 tablespoons of the cheese.
- To trim the green garlic, cut off and discard the tough, dark green leafy tops, which resemble the tops of leeks. You will use only the white and pale green part of the stalks. Cut the trimmed stalk in half lengthwise, then slice thinly crosswise. Put the sliced garlic in a large pot of cold water and swish well to dislodge any dirt. Lift the garlic into a sieve or colander with your hands or with a wire-mesh skimmer. Let drain.
- Melt 2 tablespoons of the butter in a large skillet over moderately low heat. Add the green garlic and season with salt and pepper. Stir to coat with the butter, then cover with a round of parchment paper and the lid, reduce the heat to low, and cook until the green garlic is meltingly tender, about 20 minutes, uncovering to stir occasionally.
- While the green garlic cooks, melt the remaining 4 tablespoons butter in a small saucepan over moderately low heat. Add the flour and whisk to blend. Cook, whisking, for about 1 minute, then add the milk gradually, whisking constantly. Add the thyme sprigs. Adjust the heat to maintain a gentle bubble and cook, whisking often, for about 5 minutes to allow the bŽchamel to thicken and to infuse it with the herb flavor. Stir in the nutmeg. Remove from the heat and let cool for 10 minutes.
- Whisk the egg yolks, one at a time, into the bŽchamel. Whisk in the 1⁄4 cup cheese, then season with salt and pepper. Remove the thyme sprigs, and stir the cooked green garlic into the bŽchamel base.
- With an electric mixer or by hand, beat the egg whites to firm but not stiff peaks. Fold the whites, one-third at a time, into the base. Transfer the soufflŽ mixture to the prepared baking dish, spreading it evenly. Top with the remaining 2 tablespoons cheese.
- Bake until the soufflŽ is well puffed, firm to the touch, and golden brown, 17 to 18 minutes. Serve immediately.