Prep Time: 25 minutes
Cook Time: 40 minutes
Total Time: 1 hour, 5 minutes
Serves: Makes 6 Souffles
Ingredients:
1 1/2 tablespoons plus 2 tablespoons softened butter, divided
3 tablespoons grated Parmesan cheese
½ cup finely chopped white onion
1 clove garlic, finely chopped
1 cup sweet potato puree
1 tablespoons all-purpose flour
½ teaspoon salt
1/2 cup whole milk
½ teaspoon dried thyme
1/8 teaspoon ground black pepper
¾ cup shredded Gruyere cheese
3 eggs, separated
Preparation:
How to make sweet potato souffle:
Brush the inside of a large soufflé or deep casserole dish with 1 1/2 tablespoons of softened butter. Sprinkle the buttered surface evenly with Parmesan cheese and set aside the dish.
Preheat the oven to 375F. In a large saucepan over medium heat, sauté the onions and garlic in the remaining butter until they turn translucent and tender. Add the flour and salt to the tender onions and garlic. Cook the flour, whisking constantly, for 30 seconds. Add the milk to the flour and cook, still whisking constantly, for about 4 minutes, until the mixture thickens. Add the sweet potato puree, dried thyme, and black pepper and continue cooking over medium heat for 1 minute. Remove from the heat and stir in the Gruyere cheese.
Whisk ½ cup of the hot sweet potato mixture into the egg yolks, and then add the egg yolk mixture back into the hot sweet potatoes, stirring to completely incorporate. Beat the egg whites on high speed until stiff peaks form. Stir one-third of the egg whites into the sweet potatoes, and then fold the remaining egg whites into the mixture. Spoon it into the prepared dish and bake for 30 minutes, until the sweet potato soufflé is puffed up and cooked through.