This is a very versatile recipe. I make this kind of soufflé also with butternut squash or pumpkin instead of sweet potatoes, and with apples, apricots, or peaches instead of pears. The flavoring for the puree can be also in other combinations: orange-ginger or lime-cayenne. You can use different herbs, such as mint, marjoram, parsley, or cilantro and bake the soufflé in 3/4-cup ramekins.
For orange-ginger flavoring: Add 1/4 cup each milk and orange juice, 2 tablespoons melted butter, and 2 teaspoons minced fresh ginger.
For lime-cayenne flavor: Add 2 tablespoons lime juice and a large pinch of cayenne. —Kukla
Test Kitchen Notes
The flavor in this soufflé certainly raises the bar well above the ones I’ve had the pleasure of meeting thus far, and sets it pretty high for those in my future. The sweet potato, pear, and maple syrup play off each other like the yellows, reds, and oranges of an autumn drive through New England. I do think the recipe could do with an additional egg white or two to help lift the weighty base a little further out of the dish - cheese1227 —cheese1227
6 to 8
For the Soufflé base
butter, plus more for baking dish
small onion or 2 shallots, finely chopped
garlic cloves, minced
fresh thyme leaves
Coarse salt and ground pepper to taste
whole milk, hot
coarsely grated Gruyere cheese
finely grated Parmesan cheese for the baking dish
extra-large eggs, separated + 1 more egg white
For the Pear and Sweet Potato Puree
firm but ripe Bartlett pears, peeled, cored and cut into 1/4-inch slices
Peel and cut sweet potatoes into 1-inch chunks. In a large saucepan, cover potatoes with water. Bring to a boil; cook until tender when pierced with the tip of a paring knife, 15 to 20 minutes. Drain.
Heat butter in a large skillet over medium heat. Add pears; cook, stirring occasionally, until soft and just golden, 12 to 20 minutes. Pour in maple syrup; cook, stirring, until pears are coated and very soft, 3 to 5 minutes.
Puree the potatoes and pears in food processor, transfer to a bowl, set aside.
Preheat oven to 375° F degrees. Butter a soufflé baking dish and sprinkle the bottom and the sides with Parmesan cheese. Set aside.
In a medium saucepan, melt butter over medium-low heat. Add onion, garlic, and thyme; season with salt and pepper. Cook, stirring often, until onion is softened, about 8 minutes. Stir in flour; cook, stirring, 3 minutes.
Gradually whisk in milk; simmer, whisking constantly, until thickened, about 2 minutes. Remove from heat, and stir in Gruyere cheese and 1 teaspoon salt.
Whisk in sweet potato and pear puree, orange zest, and then egg yolks, one at a time. Taste and add more salt and pepper if needed.
In a clean mixing bowl, beat egg whites with a pinch of salt until stiff peaks form. Whisk 1/4 of whites into cheese, sweet potato, and pear mixture. Using a rubber spatula, gently fold in the rest.
Place soufflé baking dish on a rimmed baking sheet. Pour in mixture, smooth out the top. Bake until puffed and golden brown, 35 to 40 minutes.
Serve immediately with more butter and Maple Syrup.