Leek, Spring Herb and Cheese Soufflé Casserole
By Amy Maltzan, adapted from Martha Stewart
One of my favorite breakfast/brunch dishes…though I make it equally as much for a light dinner, and look forward to leftovers for lunch the next day.
1 tablespoon plus 1 stick unsalted butter, plus more for dish
1 pound leeks (white and pale-green parts only), quartered lengthwise, cut into 1/8-inch slices and rinsed well (about 4 cups)
salt and pepper, to taste
1/2 cup plus 2 tablespoons Parmesan cheese, finely grated
1/2 cup all-purpose flour
2 1/2 cups whole milk
6 large eggs, separated
5 1/2 ounces Gruyere cheese, grated (1 1/2 cups)
1 tablespoon finely chopped fresh parsley
1 tablespoon finely chopped fresh dill
1 tablespoon finely chopped fresh chives
Melt 1 tablespoon butter in a large skillet over medium-high heat, then add leeks and cook, stirring often, until softened and bright green, about 3 minutes. Season with salt and pepper; let cool. (Leeks can be made 1 day ahead and refrigerated.)
Butter a 9-by-13-inch baking dish. Place 1/2 cup Parmesan in dish, and tilt dish to coat bottom and sides well. Pour out and discard excess cheese.
In a heavy saucepan over medium heat, melt 1 stick butter. Whisk in flour and cook, whisking constantly, for 1 minute or until well combined and heated. Gradually add milk, whisking constantly until batter is very smooth. Add 1 teaspoon salt, season with pepper, and continue whisking until soufflé base is smooth, shiny and thick, about 12 minutes.
Preheat oven to 400º. Transfer soufflé base to a bowl, and beat in egg yolks 1 at a time, beating thoroughly after each addition. Add Gruyere, the remaining Parmesan, leeks and herbs and beat until well combined.
In the bowl of a stand mixer using the whisk attachment, beat egg whites with 1/2 teaspoon salt until stiff peaks form (you can also do this by hand if you don’t have a stand mixer, though it will take a little longer!) Fold whites gently but thoroughly into soufflé base, one-third at a time (a few streaks of whites may remain and that’s fine.) Spoon soufflé mixture into baking dish; bake until puffed and golden, 35 to 40 minutes.
Amy Maltzan is an avid home cook, gardener and occasional blogger. More of her seasonally focused recipes are available at eggsonsunday.wordpress.com.
Photo by Amy Maltzan