Cheesy, savory, and naturally sweet, these Scalloped Sweet Potatoes are a comforting and easy to make side dish! This dish is made without a roux and is super simple to make.
Serve for family dinner, Sunday dinner, Christmas, or Easter.
Article Summary:
In today's post, we will be making scalloped sweet potatoes (also known as "sweet potatoes au gratin"). This satisfying side dish is a unique take on traditional scalloped potatoes. Read on to learn how to make the recipe, common FAQs, and more!
Table of contents
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Feeling the need for some cozy, hearty, and savory comfort food? Then, join me in making this sweet potato au gratin with gruyere cheese!
With just a few simple steps and an approachable ingredient list, this side dish is as perfect for an easy Tuesday night dinner as it is for a an elaborate holiday meal.
Gruyere, though it sounds fancy, is a type of Swiss cheese that is fairly easy to find at most supermarket chains and Whole Foods here in the United States (I usually get mine at Trader Joe's). If you have any trouble finding gruyere cheese, just ask the deli attendants or cheesemonger.
Let's chat about this sweet potato gratin:
- Homey. This is the kind of dish we want on a snowy evening or a Fall or winter Sunday dinner with friends and family. It's rich and cheesy and perfectly enhanced with herbs and onions to taste like comfort in a bowl.
- Easy to make. If you can slice potatoes, whisk flour and milk, and sprinkle seasonings, you can make this dish! There is no complex cheese sauce required for this dish. Instead, the flour thickens up the milk as it bakes.
- Perfect for holidays. The naturally-sweet and cheesy flavors go so well with most holiday main dishes like ham, roasted turkey, or lamb. It's also an impressive dish to add to the holiday spread. See my notes below for how to save yourself time and make this dish ahead of time.
- A family favorite. I first served this dish to my family for Thanksgiving. It was such a hit that I also now serve it for Easter and Christmas! Almost everyone -- from kids to adults -- will find something to love about this dish!
Ingredients:
- Sweet potatoes
- Yellow or white onion
- Gruyere cheese (shredded) - since pre-shredded Gruyere is often hard to find, I recommend buying a block of it and shredding it with a cheese grater.
- Unsalted butter
- Milk - preferably 1% or 2% milk
- All-purpose flour
- Dried thyme
- Salt
Substitutions:
- Potatoes - this recipe is the best with sweet potatoes, but if you are running low, you can substitute peeled and sliced golden (or Yukon gold) potatoes for half of the sweet potatoes
- Cheese - shredded Swiss cheese or provolone can work in place of the Gruyere, though the flavor profile will be slightly different. Ask for a block of Swiss cheese or provolone in the deli area if you can't find a block of either in the cheese department of your grocery store.
- Thyme - fresh thyme can replace the dried thyme. Just use 3 times the amount of fresh herbs that you would use dry (or 1 ½ teaspoon of fresh thyme).
How to make au gratin sweet potatoes...
- Preheat the oven.
- Spray an 8 x 8-inch baking dish with non-stick cooking spray or grease with butter.
- Layer ⅓ of the sliced sweet potatoes in the baking pan. Sprinkle with ⅓ of the onions, salt, dried thyme, gruyere cheese, and butter.
- Repeat layering the ingredients 2 times, forming 3 layers of potatoes with seasonings and cheese.
- In a mixing bowl, vigorously whisk together the milk and flour.
- Pour the milk mixture over the sweet potatoes in the baking dish.
- Cover the pan with aluminum foil or the baking dish lid.
- Bake the sweet potatoes covered for 30 minutes.
- Remove the foil or the lid from the baking pan. Bake another 30 minutes, or until the cheese is golden brown and the potatoes are cooked through.
- Let the sweet potatoes rest at room temperature until the cheese sauce has thickened up.
- Serve hot!
Recipe pro-tips:
- Cut the sweet potatoes uniformly. No need for perfection, but try to cut the sweet potatoes as uniformly as you can. This will help them bake evenly. You can also use a mandoline slicer to cut the sweet potatoes, though be careful with your fingers if doing so (they can be very sharp!).
- Whisk the flour and milk together well. You want to mix it vigorously enough together that the milk gets frothy and the flour is completely dissolved into the milk, possibly for up to 30 seconds. If you'd rather save yourself from all the whisking, you can also blend the milk and flour together in a blender for 15-20 seconds.
- Rest the sweet potatoes before serving, at least 5 minutes. This allows the cheese sauce to thicken up and absorb into the potatoes.
Recipe FAQs:
You can tell the scalloped potatoes are done when the potatoes are tender when pierced through in the center of the dish with a sharp knife. At this point, the sauce should also be golden brown and bubbly.
Yes, you can this dish ahead of time. Just assemble the dish, cover, and refrigerate for up to 2 days before baking as directed.
Serving suggestions:
Serve these scalloped sweet potatoes au gratin almost anywhere you would serve mashed potatoes or roasted potatoes as a side. They are fantastic with:
- Grilled steak
- Roasted meats or pork tenderloin
- Roasted turkey
- Ham
- Smoked or grilled chicken
- Roasted vegetables
- ... and more!
Storage directions:
Store the leftovers covered in the refrigerator for 4-5 days. They do not freeze well, unfortunately.
Dietary adaptations:
These potatoes can be made gluten-free by substituting a 1-to-1 gluten-free flour mix for the all-purpose flour. The sauce will be slightly thinner but the overall dish and flavor will be the same.
Tools needed to make this recipe:
- Cutting board
- Chef knife
- Measuring cups & spoons
- Mixing bowl
- Whisk
- Cheese grater (optional)
- 8 x 8-inch baking dish
More Sweet Potato Recipes:
- Dutch Oven Sweet Potatoes
- Candied Whipped Sweet Potatoes
- Sweet Potato Casserole
- Crispy Roasted Sweet Potatoes with Miso Maple Glaze
- Quinoa and Roasted Sweet Potato Salad
- Ground Turkey and Sweet Potato Skillet
If you made and liked this recipe, don't forget to rate the recipe and let me know how it went for you in the comments! It always makes my day to hear from you!
Scalloped Sweet Potatoes
Email FacebookIngredients
- Non-stick cooking spray
- 3 medium sweet potatoes peeled and sliced into thin (⅛") rounds
- ½ medium yellow or white onion sliced into thin rings
- ¾ teaspoon salt
- ½ teaspoon dried thyme
- 1 ¾ cup shredded gruyere cheese
- ¼ cup unsalted butter cut into small cubes
- fresh cracked black pepper
- 2 ¼ cup 1% or 2% milk
- 6 tablespoons all-purpose flour
Instructions
- Preheat the oven to 375 degrees Fahrenheit.
- Spray an 8 x 8-inch baking dish with non-stick cooking spray or grease with butter. Layer ⅓ of the potatoes in the pan. Sprinkle with ⅓ of the onions, salt, dried thyme, gruyere cheese, butter, and freshly cracked pepper. Repeat 2 times, continuing to layer ⅓ of the ingredients each time.
- In a large mixing bowl, vigorously whisk together the milk and all-purpose flour until a frothy mixture forms and all of the flour has dissolved in the milk.
- Immediately pour the milk mixture over the layered potatoes in the baking pan.
- Cover the baking dish with aluminum foil or the baking pan lid. Bake for 40 minutes.
- Remove the foil or lid from the baking dish and bake for 30-35 minutes more, or until the cheese is golden brown and the potatoes are cooked through.
- Rest the potatoes at room temperature for 5-10 minutes, or until the cheese sauce has thickened up. Serve hot!
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