- 3 lbs large sweet potatoes (1365 g)
- 6 tablespoons unsalted butter, softened (90 g)
- ½ cup heavy cream (116 g)
- ½ cup shredded gruyere cheese (50 g)
- 2 tablespoons light brown sugar (30 g)
- 1 teaspoon chopped thyme (5 g)
- Salt
- Fresh ground pepper
- 3 large eggs
- Preheat the oven to 350° Fahrenheit and bake the sweet potatoes for 90 minutes or until tender. Increase oven temperature to 425° Fahrenheit.
- Take out sweet potatoes from the oven when done baking. Peel them as soon as they are cool enough to handle and transfer into a large bowl.
- With a hand held electric mixer, mash sweet potatoes with butter until smooth.
- Stir in cream, Gruyere, brown sugar, and thyme into the mixture. Sprinkle with salt and pepper. Add the eggs one at a time, beating well after each addition.
- Transfer the sweet potato mixture to a buttered, 8 x 10 inch baking dish and bake for 15 minutes. Reduce oven temperature to 400 degrees F and bake for 30 minutes longer or until the soufflé is lightly puffed and browned. Let it stand for 10 minutes before serving.
- Serve and enjoy!