I love sweet potatoes but like to prepare them with a savory rather than sweet (i.e., with maple syrup and/or cinnamon) bent, which is why I've used thyme and Gruyere cheese in this souffle. I serve it with a pile of sauteed greens, such as chard or kale, and Honey-Buttermilk Biscuits (recipe below).
Makes 6 servings
2 pounds sweet potatoes (about 2 large sweet potatoes)
3 tablespoons unsalted butter
1 medium yellow onion, minced
1 1/2 cups whole milk
3 tablespoons all-purpose flour
6 large eggs, separated
1 cup shredded Gruyere cheese
1/2 teaspoon dried thyme, or one teaspoon fresh thyme
Salt and pepper, to taste
Preheat oven to 375 degrees.
Fill a medium-sized saucepan with water and add the sweet potatoes. Bring to a boil, then simmer until potatoes are soft. Drain and mash well to form a smooth puree.
Butter a 2-quart souffle dish.
In a large saucepan over medium heat, melt the butter. Add the onion and saute, stirring occasionally, until soft, about 5 minutes. Meanwhile, in a small saucepan over medium heat, warm the milk until small bubbles appear along the edges of the pan, then remove from heat. Add the flour to the onion and cook, stirring constantly, for 3 minutes. (Do not brown.) Whisk in the milk all at once and simmer, continuing to whisk, until thickened, 2 to 3 minutes. Remove from the heat and add the egg yolks one at a time, beating well after each addition. Add the sweet potato puree, Gruyere cheese, thyme, salt and pepper to taste. Stir until well blended.
In a large bowl beat the egg whites with a pinch of salt on high speed just until stiff peaks form. Using a rubber spatula, fold one-fourth of the egg whites into the sweet potato mixture to lighten it. Then fold in the remaining whites just until no white streaks remain. Pour into the prepared souffle dish.
Bake until puffed and golden, 45 to 50 minutes. Serve immediately.
Light and lightly laced with the flavors of honey and buttermilk, these biscuits are lovely served alongside slices of sweet potato souffle, or toasted in the morning with jam and a cup of coffee. Try not to overwork the dough, but knead in just enough flour so it is no longer sticky before rolling out and cutting.
Makes 12 biscuits
2 1/2 cups all-purpose flour
1/2 cup whole-wheat flour
1 tablespoon baking powder
1 teaspoon sugar
1 teaspoon salt
3/4 cup (1 1/2 sticks) unsalted butter, cubed
2 tablespoons honey
1 cup buttermilk
Preheat oven to 350 degrees.
In a large bowl, whisk together flours, baking powder, sugar and salt.
Cut in the butter using a fork or your hands, until the mixture is crumbly and small "peas" form. Add honey and buttermilk and stir well until a sticky dough forms.
Turn the dough onto a lightly floured surface and lightly knead in a bit of flour until it is no longer sticky. Roll out dough until it is about 1 inch thick. Using a biscuit cutter (or a small glass), cut dough and place biscuits on a baking sheet lined with parchment paper. Gather remaining scraps, knead together and roll out, cutting biscuits until there is no more dough.
Bake biscuits for 20 minutes or until golden brown. Serve hot.