Name: Sweet Potato Gratin
Prep time: 15 min
Cook time: 75 min
Ingredients: 1 large/medium sweet potato (sliced thin with a mandolin); 2-3 medium yukon gold potatoes (sliced thin with a mandolin); 32 oz heavy cream (more or less if needed - enough to slightly cover top layer); 4 sprigs fresh thyme (+ additional for garnish); 1 tbsp minced garlic (~3-4 cloves); dash of salt & pepper

Sweet Potato Gratin with layers of thinly sliced sweet potatoes and buttery yukon gold baked in a garlic and thyme infused cream. Golden and crisp potato chips top the dish off for extra flavor and crunchy texture. I love the contrast between the soft and creamy potato base and the crumbled potato crisps overtop. Truly a match made in heaven for texture and flavor!

Not only is this sweet potato au gratin cozy and tasty, it’s also made with less than 10 ingredients to be extra simple. Throw this in for a quick, low maintenance meal and enjoy the leftovers throughout the week. Andy and I love making this for a busy week or even as an easy dish for family and holiday gatherings!

For more potato inspired meals be sure to check out this Warm Roasted Garlic Potato Salad that’s filled with fresh vegetables and tossed in a creamy garlic dressing. Or my Gluten Free Sweet Potato Gnocchi that’s so simple and even better than the Trader Joe’s version! Both are great options for a quick meal or an easy side dish.

Sweet potato gratin with soft, thin sliced potato layers covered in a herbed garlic cream sauce. The top layer is baked golden with crumbled gluten free potato crisps overtop. Fresh sprigs of thyme garnish the dish as a wooden spoons rests within the pan to serve.

Ingredients

Sweet Potatoes – Add a slight sweet flavor and extra creamy texture to this sweet potato gratin recipe.

Yukon Gold Potatoes – Have a great buttery flavor to them and also create an extra creamy texture. You can always sub for another potato though if needed.

Heavy Cream – Makes these homemade au gratin potatoes extra creamy and thick. To make dairy free sub with something like this nutpods unsweetened creamer.

Thyme – Fresh is best but if you need to use dried only use 2 teaspoons of dried thyme.

Garlic – Fresh minced garlic yields the best flavor but if you’re using garlic powder only use up to 3/4 tsp.

Cheddar Crisps – These are optional but add such great flavor and crisp! My favorite brand to use is The Good Crisp Company because their Aged White Cheddar flavor pairs perfectly with this sweet potato gratin + they’re gluten free.

A baking dish of sweet potato gratin sits with a wooden spoon for serving. The au gratin is made with alternating layers of thin sliced sweet potato followed by yukon gold potato. An herbed garlic cream sauce is baked with the layers and crumbled potato crisps top it. Fresh sprigs of thyme garnish the dish. Below the dish is a small bowl of salt and fresh thyme. To the left are two glasses of water and above the dish are more plates for serving plus a small bowl of red pepper flakes.

How to Make Sweet Potato Gratin

1. Preheat oven to 375F.

2. In a 2-3 inch deep, 9×13” pan spread one layer of sweet potato slices. Sprinkle with salt & black pepper. Alternate with layer of yukon gold potatoes. Sprinkle with salt & black pepper. Repeat process until you have used all potatoes. You want to leave at least 1/2” space from the top of the pan so it doesn’t overflow.

3. Whisk together heavy cream, minced garlic, and fresh thyme. Pour over the potato slices. You want to ensure the top layer is fully covered with liquid.

4. Move to the oven and bake at 375F for 1 hour and 15 minutes. Check the potatoes – if there is still a lot of liquid, increase temp to 400F and continue baking until top is a light golden brown.

5. Optional: Top with crushed GF aged cheddar crisps, move back to the oven, and continue baking until a deep golden brown, another 5-10 minutes.

6. Remove from the oven and let sit for 10 minutes before serving. Garnish with extra fresh thyme. Enjoy!

A stainless steel baking dish is filled with layers of thin sliced potato rounds. The base layer is sweet potato, followed by yukon gold, then topped with a final layer of sweet potato.

A stainless steel baking dish is filled with layers of thin sliced potato rounds. The base layer is sweet potato, followed by yukon gold, then more sweet potato, then topped with a final layer of yukon gold potatoes.

Vegan Potatoes Au Gratin

Although this sweet potato gratin is already gluten free and made with better-for-you ingredients, the recipe itself is not vegan. However, you can make it into vegan potatoes au gratin with one simple swap!

Instead of using heavy cream sub for a dairy free alternative. The key is to find a creamy and thick planted based blend to achieve the same texture. I’d suggest this nutpods unsweetened creamer which is what I used in my regular Easy Au Gratin Potatoes recipe.

This unsweetened, vegan creamer from Picnik is also another great option for a thick and creamy base. Or try this dairy free Silk Heavy Cream Alternative although I personally have not tried it.

You could also just use any other unsweetened, dairy-free creamer that you already enjoy. Whatever you end up doing, comment below and let us know how it worked for you!

Gluten free au gratin potatoes with an herbed garlic cream sauce. The top layer is baked golden with crumbled gluten free potato crisps overtop. Fresh sprigs of thyme garnish the dish as a wooden spoons rests within the pan to serve. A plate with more potato crisps sits to the side of the pan as well as a small bowl of salt and fresh sprigs of thyme.

Do Sweet Potatoes Take Longer to Cook Than Regular Potatoes?

Surprise, they actually take less time! Sweet potatoes are naturally softer than regular potatoes so they require even less time to cook. I still suggest slicing the sweet potato into thin rounds with the mandolin as the thinner the better.

I find that the trick to ensure the cooking time isn’t too long is to use a more shallow pan. This will have a faster cook time than a deeper dish.

A stainless steel pan of baked au gratin potatoes sit with a wooden spoon dipped in for serving. The layers of thin sliced sweet potato and yukon gold potato are covered in an herbed garlic cream sauce. The top layer is baked to a crisp with crumbled potato chips overtop. To the right of the pan is a plate of more chips. a glass of water, a bowl of salt, and fresh sprigs of thyme. To the left of the pan are more plates for serving, a water glass, a small bowl of red pepper flakes, garlic cloves, and fresh sprigs of thyme.

Best Mandoline Slicer

Homemade au gratin potatoes just wouldn’t be the same without the thin layers of soft baked potatoes. I mean there’s nothing better than biting through the soft yet crisp and flavorful layers of potato with cream. It’s a whole other reason to love these easy gluten free au gratin potatoes!

The key to creating great layered texture and flavor is to use a mandoline slicer for a nice thin slice. I think this is the easiest and safest way to slice the potatoes. Just be careful, sharp objects are always sharper than we realize and way too easy to get cut on lol, not like I’m talking from personal experience or anything … 😉

A few options for effective mandoline slicers include this one from Oxo or this Swissmar set on amazon. The blades are sharp yet the design is designed in a proper safe way. If you don’t have a mandoline feel free to slice the potato rounds with a knife, just be careful once more!

Top down shot of baked sweet potato gratin in a baking dish with a wooden spoon for serving. The layers of thin sliced sweet potato and yukon gold potato are covered in an herbed garlic cream sauce. The top layer is baked to a golden crisp with crumbled potato chips overtop. Surrounding the pan is a plate of more chips. two glasses of water, a bowl of salt, fresh sprigs of thyme and a small bowl of red pepper flakes.

For any leftover sweet potato au gratin, simply store in an airtight container for up to 7 days in the fridge or 3 months in the freezer. If freezing, portion into servings beforehand so that it’s easier to thaw!

And for more easy, healthy meals to make for the week ahead or as a cozy night in, check these out. My Healthy Eggplant Parmesan is saucy, cheesy, and oh so easy. The kick of heat in the arrabbiata sauce pairs perfectly with the soft baked eggplant and melty mozzarella cheese. Yum!

For an even simpler dish that’s just as tasty, my 6 Ingredient Vegan Alfredo is the way to go. It’s made with a cashew base and is lighter than most recipes while still tasting “cheesy” thanks to the nutritional yeast.

Homemade au gratin potatoes with a thin layers of alternating sweet potato and yukon gold potato rounds. The au gratin is made creamy with an herbed garlic sauce that can also be made vegan. The top layer has a golden char to it from baked potato crisps on top. To the left of the au gratin dish is a small bowl of salt and fresh sprigs of thyme. Above the dish are two glasses of water.

If you try this recipe, please let me know by leaving a comment and rating in the boxes below! I always love to hear from you and it helps other people find this recipe when they search online for the BEST Sweet Potato Gratin 🙂