This savory Sweet Potato Gratin is inspired by Pommes Anna, a French dish of creamy, thinly sliced potatoes with rich buttery flavor topped with melted Gruyere cheese.
Savory Sweet Potato Gratin
There’s no milk or cream in this Sweet Potato Gratin, yet the texture is so buttery and creamy while keeping it as low calorie as possible. Instead of a saucy gratin with loads of cream and calories, these sweet potatoes are thinly sliced like Pommes Anna and topped with cheese to make it a classic gratin. I love the texture of the super thin potatoes, and the leftovers are even better. For more healthy gratin recipes, try my Spinach Gratin, Potato Gratin, and Brussels Sprouts Gratin.
Why This Sweet Potato Au Gratin Recipe Works!
- Lighter and Healthier Than Most Gratins: This sweet potato gratin without cream or milk still gets nice and creamy in the oven. There’s just enough butter to taste it and make the dish rich.
- Prep Ahead: You can make most of this dish beforehand, so you have less to do on Thanksgiving. Keep reading for my tips for making it in advance!
- Oven to Table: It’s a beautiful dish that can go from the oven to the table. Slice it like a pie and let everyone serve themselves.
Sweet Potato Gratin Ingredients
- Sweet Potatoes: Peel two pounds of sweet potatoes and slice them as thinly as possible. I cut them to 1/8-inch thick with a mandolin while wearing a cut-resistant glove.
- Butter: Melt two tablespoons of butter.
- Thyme: Chop fresh thyme leaves.
- Salt and Pepper to season the potatoes
- Cheese: Grated parmesan and Gruyere cheese
How to Make Sweet Potato Gratin
- Coat the Potatoes with melted butter and season with thyme, salt, and pepper.
- Layer the Potatoes in a gratin or pie dish, pressing them down to keep them at an even thickness.
- Sprinkle both cheeses evenly over the top.
- Bake the Gratin: Spray a piece of foil with oil and cover the pan with it, oiled-side down. Bake the grating for 30 minutes at 425°F, uncover, and bake for another 15 minutes until the potatoes are tender and the cheese is melted.
- Herbs: Swap thyme with rosemary or sage.
- Potatoes: Substitute Yukon Gold potatoes.
- Cheese: Switch out the Parmesan with Pecorino Romano or Gruyere with Swiss.
What is the gratin technique?
Gratin is a term for a dish with a breadcrumb or cheese topping that’s baked until crispy. Potato gratin is the most popular, but there are many variations with different vegetables, like this fennel gratin, butternut squash gratin, and spinach gratin.
What to Serve with Sweet Potatoes Gratin
- Holidays: Dry Brine Turkey, Turkey Gravy, Stuffing, Green Bean Casserole
- Protein: Whole Roasted Chicken, Air Fryer Bacon-Wrapped Pork Tenderloin, Turkey Meatloaf
- Vegetables: Roasted Broccoli with Smashed Garlic, Fall Brussels Sprout Salad, Roasted Green Beans with Parmesan
How to Make Ahead
If you’re hosting Thanksgiving, Christmas or any dinner, you can prep most of this dish ahead of time to make the holiday less stressful.
- The day before, bake the dish without the cheese for 30 minutes. Let it cool and refrigerate it.
- When you’re ready to reheat it, cover it with foil and bake until warm.
- Then top with cheese and bake for 15 minutes.
How to Store Gratin
Store potato gratin in an airtight container for up to 4 days in the refrigerator or 3 months in the freezer. Microwave leftovers until warm.
More Sweet Potato Recipes You’ll Love
- Mashed Sweet Potato Brulee
- Roasted Sweet Potatoes
- Sweet Potato Casserole with Praline Topping
- Mashed Sweet Potatoes
- Twice Baked Sweet Potatoes
Sweet Potato Gratin Recipe
- Preheat the oven to 425°F. Coat a round pie dish or other 6-cup gratin dish with olive oil spray.
- Peel the sweet potatoes and slice them as thinly as you can manage, I did them 1/8th inch thick with a mandolin. Put the slices in a large bowl and add the melted butter, thyme, salt, and pepper to taste. Toss to make sure all the slices are well coated.
- Take a handful of potatoes and arrange them in a layer on the bottom of the baking dish. Keep adding more layers, one handful of potatoes at a time and as you work, press the potato slices down and try to keep them in an even thickness all around. Once all the slices have been added, press down gently to compact them a bit.
- Sprinkle the Parmesan cheese and Gruyere evenly over the top. Spray one side of a piece of aluminum foil with olive oil spray and cover the pan with aluminum foil, oiled-side down (to prevent the cheese from sticking).
- Bake the gratin for 30 minutes. Uncover and continue to bake until the potatoes are tender when pierced with a knife and the cheese is melted, about 15 minutes.
- Let it rest for 5 minutes before slicing and serving.