Sweet Potato Gratin

5 from 10 votes
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This Sweet Potato Gratin is simply irresistible, thanks to its creamy, cheesy, and perfectly seasoned sauce. It’s the ideal side dish that brings a touch of indulgence to any meal!

Side shot of sweet potato gratin in a white baking dish.


You’re about to fall in love with this Sweet Potato Gratin! We’ve taken sweet potatoes to the next level by layering them in a dreamy, cheesy sauce, and it’s a dish that feels indulgent but not too heavy, brimming with delicious flavors and textures. Perfect for dressing up your dinner or impressing at a potluck, this gratin will surely be a hit!

Why We Love This Recipe

  • Creamy and Cheesy: With layers of sweet potatoes enveloped in a rich, cheesy sauce, it’s a delightful balance of flavors.
  • Lightened-Up Comfort: Enjoy the comfort of a classic gratin without the heaviness, thanks to the use of evaporated milk.
  • Perfect Make-Ahead Dish: Prepares ahead of time and allows flavors to meld, freeing up oven space for other dishes.
Overhead image of baked Sweet Potato Gratin covered in melty cheese.

Sweet Potato Gratin Ingredients

  • Sweet Potatoes: Thinly sliced for layered texture and natural sweetness.
  • All-Purpose Flour: Helps thicken the sauce for a creamy consistency.
  • Seasonings: Salt, pepper, ground ginger, nutmeg, paprika, dried rosemary, and thyme.
  • Evaporated Milk: A lighter alternative to heavy cream.
  • Parmesan Cheese: Adds a nutty, salty depth to the gratin.
  • Swiss Cheese or Gruyere Cheese: Brings a melty, gooey texture and rich taste.

How To Make Sweet Potato Gratin

  1. Preheat oven to 350°F and grease a 9-inch baking dish with butter or cooking spray.
  2. Toss sliced sweet potatoes with flour, seasonings, and thyme in a large bowl.
  3. Layer the sweet potatoes in the baking dish, sprinkling parmesan and drizzling evaporated milk between layers.
  4. Top with Swiss or Gruyere cheese, cover with foil, and bake for 35 minutes.
  5. Remove foil and bake for an additional 25 minutes until browned and bubbly.
  6. Let cool for 30 minutes and garnish with extra parmesan and dried parsley before serving.
Wooden spoon lifting out a serving of sweet potato gratin from a baking dish.

Recipe Tips And Variations

  • Slice Evenly: For even cooking, make sure your sweet potato slices are of uniform thickness. Using a mandoline slicer can help achieve consistent slices.
  • Layering Technique: When layering the sweet potatoes in the dish, slightly overlap the slices.
  • Cheese Choices: Feel free to experiment with different types of cheese for varied flavors. A mix of sharp and mild cheeses can add depth to the gratin.
  • Add a Crunchy Topping: For a bit of texture, consider adding a breadcrumb and parmesan mix on top during the last few minutes of baking.
  • Spice It Up: Adjust the spices to suit your preference, adding more heat or aromatic herbs as desired.

Serving Suggestions

When it comes to serving Sweet Potato Gratin, it pairs exceptionally well with my extra buttery oven roasted turkey, this air fryer rotisserie chicken, my famous tender pork loin, or a juicy beef tenderloin! For a lighter fare, try serving it alongside this chef salad, chopped salmon salad, or this popular la scala chopped salad.

Spooning out sweet potato slices with a wooden spoon.

Easy Festive Side Dishes

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5 from 10 votes

Sweet Potato Gratin

This Sweet Potato Gratin is simply irresistible, thanks to its creamy, cheesy, and perfectly seasoned sauce.
Prep Time: 10 minutes
Cook Time: 45 minutes
Resting Time: 10 minutes
Total Time: 1 hour
Servings: 6


  • 2 pounds sweet potatoes,, thinly sliced
  • 2 tablespoons all purpose flour
  • salt and fresh ground black pepper,, to taste (I add about 1 teaspoon of salt and 1/2 teaspoon black pepper)
  • ½ teaspoon dried thyme
  • ½ teaspoon dried rosemary
  • ½ teaspoon paprika or chili powder
  • ¼ teaspoon ground ginger
  • ¼ teaspoon ground nutmeg
  • 1 can (12 ounces) evaporated milk
  • ¼ cup grated parmesan cheese
  • ½ cup grated swiss cheese or gruyere cheese
  • grated parmesan cheese for garnish,, optional
  • parsley,, for garnish, optional
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  • Preheat oven to 350˚F.
  • Lightly grease a 9-inch baking dish with butter or cooking spray and set aside.
  • In a large bowl, combine the sliced sweet potatoes, flour, salt, pepper, thyme, rosemary, paprika, ginger, and nutmeg; toss to combine.
  • Arrange one layer of sliced sweet potatoes, overlapping slightly, on the bottom of the baking dish.
  • Sprinkle with a bit of parmesan and pour about 1/4 cup of evaporated milk.
  • Repeat layers with remaining sweet potatoes, parmesan, and milk.
  • Top with swiss or gruyere cheese.
  • Cover with foil and bake for 35 minutes.
  • Remove foil and continue to bake for 20 more minutes or until the top is browned and bubbly and the potatoes are tender.
  • Remove from oven and let cool for 10 minutes.
  • Garnish with grated parmesan and dried parsley.
  • Serve.


  • Sweet Potato Slices: Cut the slices to the same thickness for even cooking.
  • Layering: Slightly overlap the sweet potato slices. This not only looks nice but ensures each bite is seasoned and flavored.
  • Season Every Layer: Sprinkle each layer of sweet potatoes with a bit of the seasoning mix.
  • Cheese Choices: Use different cheeses for varied flavors.
  • Crunchy Topping: For some crunch, add a breadcrumb mix on top during the last few minutes of baking.
  • Pre-Cooking Sweet Potatoes: If you’re short on time, parboil the sweet potato slices for a few minutes before baking. This reduces the overall cooking time in the oven.
  • Herb Variations: While thyme is classic, sage can also complement sweet potatoes.
  • Creamier Sauce: You can use heavy cream for an even creamier texture.
  • Spice It Up: Add a pinch of cayenne pepper to the spice mix.
  • Let it Rest: Allowing the gratin to rest for 10 to 15 minutes after baking helps the layers settle and makes it easier to serve.


Calories: 270kcal | Carbohydrates: 38g | Protein: 10g | Fat: 8g | Saturated Fat: 4g | Cholesterol: 28mg | Sodium: 225mg | Potassium: 688mg | Fiber: 4g | Sugar: 12g | Vitamin A: 21720IU | Vitamin C: 4.7mg | Calcium: 314mg | Iron: 1.4mg

Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.

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Recipe Rating:


  1. Catalina says:

    Such a fancy and delicious side dish for Thanksgiving dinner!

  2. Erin | Dinners, Dishes and Dessert says:

    Looks absolutely delicious! I’m excited to make this!

  3. Beth says:

    That looks absolutely delicious. I love the combination of the natural sweetness of the sweet potatoes and the savory seasonings.

  4. Erin | Dinners,Dishes and Dessert says:

    This needs to happen at my house very soon!!

  5. Kim - Today's Creative Life says:

    What a great idea! I’ve never made this with sweet potatoes!

  6. Michael Wurm Jr. says:

    This looks like heaven in a pan! Yum!!

    xo Michael

  7. Heather Seeley says:

    The combination of sweet potatoes, cheese and spices sounds sooooo good! Putting this on my list for the holidays.

  8. Valerie says:

    This sounds like a great holiday side for those who enjoy sweet potatoes. I love potatoes au gratin, although I do wish I could slice my potatoes a tiny bit thinner when I make it.

    1. Molly Harvey says:

      Use a mandolin – it works the best

  9. Carolyn says:

    That looks like a fantastic holiday side dish!

  10. A_Boleyn says:

    Delicious looking dish. I wish I had sweet or even regular potatoes in the house. I wonder if butternut squash would work. 🙂

    1. Katerina Petrovska says:

      Oh I love love love butternut squash! DO IT! haha 🙂