Though it doesn't rise as much as most traditional souffles, this version is surprisingly light, airy and redolent of sweet potato.
- 4 tablespoons butter, plus additional for greasing the baking dish
- 4 tablespoons flour
- Salt and freshly ground white or black pepper
- 1 cup whole milk
- 1/4 teaspoon ground nutmeg
- 3 eggs, separated
- 1/4 teaspoon cream of tartar
- 2 cups cooked, mashed sweet potato (with as few lumps as possible; from about 3 sweet potatoes)
Preheat the oven to 350 degrees. Generously butter a souffle dish or casserole. Have ready a larger baking pan at least 2 1/2 inches deep in which to place the souffle dish or casserole.
In a saucepan over low heat, melt the 4 tablespoons of butter. Whisking or stirring constantly with a fork, slowly sprinkle the flour over the butter, then season with salt and pepper to taste. Cook, stirring constantly, 2 or 3 minutes or until blended and bubbly. Remove the pan from the heat. Stirring constantly, slowly add the milk in a steady stream and stir until completely incorporated. Return the pan to medium heat and cook, stirring constantly, until the mixture barely comes to a boil. Add the nutmeg and stir to combine. Remove from the heat; set aside to cool.
Meanwhile, in large bowl using an electric mixer, beat the egg whites and cream of tartar until soft peaks form. Set aside.
In a small bowl, using an electric mixer and clean beaters, beat the egg yolks until very thick. Add some of the milk mixture to the yolks and stir to combine. Add the yolk mixture to the milk mixture in the pan and beat just until combined. Add the sweet potatoes and mix until combined.
Using a rubber spatula, gently fold about 1/4 of the egg whites into the batter to lighten it. Gradually and gently fold the remaining egg whites into the batter just until they are incorporated and no streaks remain. Scrape the batter into the prepared dish. Place the dish in the larger baking pan, place both on the oven rack and then pour enough hot water into the larger pan to reach a depth of about 2 inches.
Bake the souffle for 50 to 60 minutes, until puffed and golden.
From Lucie Lehmann Snodgrass.
Tested by Lucie Lehmann Snodgrass.
Email questions to the Food Section at email@example.com.