December 11, 2012

Sweet Potato Gratin

Sweet Potato Gratin

As the weather begins to nip and the days become even shorter, I find myself looking for new ways to cook sweet potatoes, which, no matter the season, remain one of my very favorite vegetables. They are simple perfection roasted with a bit of salt and pepper and perhaps a sprinkling of brown sugar, yet I’m always on the hunt for more creative applications. This Sweet Potato Gratin recipe is still simple really; at its heart a seasonal variation to the classic potatoes au gratin, spiced with garlic and thyme, and sure to become a seasonal favorite.


Sweet Potato Gratin

Sweet Potato Gratin

  • Author: Fork Knife Swoon
  • Prep Time: 20 mins
  • Cook Time: 40 mins
  • Total Time: 1 hour
  • Yield: 4-6 Servings


  • 2 lbs sweet potatoes, cleaned and peeled
  • 1/2 cup Gruyere cheese, grated
  • 1/2 cup sharp cheddar cheese, grated
  • 1-1/2 cups heavy cream (can substitute with half-and-half)
  • 1 tbsp fresh garlic, finely minced
  • 4 sprigs fresh thyme, removed from stems and finely chopped
  • 1/2 tsp ground nutmeg
  • kosher salt and freshly-ground black pepper, to taste


  1. Preheat the oven to 375 degrees F. In a sauce pan, heat the cream, garlic, thyme and nutmeg over medium-heat until heated through. Season with salt and pepper. Do not let come to a boil.
  2. Meanwhile, using a sharp knife or a mandolin, carefully slice the sweet potatoes horizontally into thin rounds, about 1/8 inch thick. In a casserole dish, place the sweet potatoes in a single layer in an overlapping pattern. Sprinkle with a third of the Gruyere and cheddar cheese. Repeat with two more layers. Slowly pour the cream mixture over the potatoes, letting it sink in amongst the layers.
  3. Bake for 34-40 minutes, until the potatoes are fork tender and the cheese is bubbly. Let stand for ten minutes. Serve warm.


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  • Reply
    November 18, 2017 at 8:19 pm

    So yummy!

    • Reply
      November 19, 2017 at 8:34 am

      Thanks, Brandi!!

  • Reply
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  • Reply
    November 24, 2016 at 8:10 am

    This gratin is specially requested by family and friends for the past 3 years. It is absolutely delicious!

    • Reply
      November 24, 2016 at 1:52 pm

      Thanks so much, Tamie! Happy Thanksgiving!!

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  • Reply
    November 27, 2013 at 7:46 pm

    Made this tonight for Thanksgiving. It looks and taste great!! I will serve it tomorrow

    • Reply
      December 2, 2013 at 2:38 pm

      Thank you so much, Stacy! So glad you enjoyed the recipe! It’s one of my favorite dishes to serve for guests at the holidays…

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  • Reply
    April 12, 2013 at 2:11 pm

    I don’t know what I did wrong, but mine turned into a groopy, oily mess. The cheese didn’t melt despite bubbling like crazy, and there was this oily goo through the whole dish. Bummer, because I was hoping to love this recipe!

    • Reply
      April 28, 2013 at 5:13 pm

      Erica, I am so sorry to hear that! I’ve made this recipe many times without anything like that happening… usually the cheese begins to melt even as I pour the warm cream mixture over the sweet potato layers. My only thought it that it could possibly be an issue with the specific brand(s) of cheese used? Alternatively, you could try melting the cheese completely in the cream mixture while it is on the stove, and then pouring that over the layered potatoes…