Yukon and Sweet Potato Gratin combines buttery Yukon gold potatoes and sweet garnet yam slices covered in a delightfully rich and creamy sauce with fresh thyme throughout. It’s baked until perfectly tender then finished with a crispy panko topping. It’s such a delicious side dish!

A serving of Yukon and sweet potato gratin on a plate

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If there was ever a stunning side dish to serve for a dinner party or at the holidays, it’s this Yukon gold and sweet potato gratin. The layers create a beautiful pattern of yellow and orange layers (or a checkerboard pattern, if you’re feeling fancy) and it’s no more difficult to make than a classic potato gratin. It’s so delicious!

Tips for Success

Garnet yams. Though they’re usually labeled as yams, garnets are actually a type of sweet potato. They usually have a reddish purple skin but are bright orange on the inside and have a lovely sweet flavor.
Yukon gold potatoes. These potatoes are ideal for this recipe. They have a classic buttery flavor and don’t become too soft when baking.
Use a mandolin. If you use a mandolin to slice the potatoes, it will make your life so much easier – and ensure everything is cut evenly.
Cut the potatoes evenly. If you don’t use a mandolin, use a sharp knife to cut the potatoes into thin, even slices. If they are thicker than 1/8 inch, you may need to increase the cooking time. Uneven slices can lead to some slices not being cooked enough.

Yukon and Sweet Potato Gratin

Layers of buttery Yukon gold potato and sweet garnet yam slices are topped with a rich, creamy sauce and a panko breadcrumb topping in this Yukon and Sweet Potato Gratin recipe. A stunning side dish for any dinner!

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Prep Time 30

Cook Time 1

Total Time 1 30

Servings: 8 people

Ingredients

3 tablespoons butter , softened and divided
2 cups heavy cream
coarse salt , to taste
white pepper , to taste
3 garnet yams , peeled and thinly sliced into 1/8-inch rounds
4 Yukon gold potatoes , peeled and thinly sliced into 1/8-inch rounds
3 teaspoons fresh chopped thyme , divided
1/4 cup panko breadcrumbs
1/4 cup grated parmesan

Instructions

Preheat oven to 375F.
Grease a 9×9-inch square baking dish with 1 tablespoon butter.
Season 2 cups heavy cream with salt and white pepper to taste and divide into two mixing bowls. Toss 3 peeled and 1/8-inch sliced yams in one bowl and 4 peeled and 1/8-inch sliced Yukon gold potatoes in the other to coat with the cream.
Slightly overlap the yams in a single layer in the prepared baking dish. Sprinkle with 1 teaspoon of fresh chopped thyme. Then slightly overlap the Yukon gold potatoes on top of the yams in a single layer, followed by another teaspoon thyme. Repeat this process until the dish is filled just below the top. (Alternatively, you can overlap both types of potatoes in each layer for more of a checkerboard look.)
Pour the cream from the bowls over the top of the dish until it sits just below the top of the potatoes/yams.
Cover tightly with foil and transfer to a rimmed baking sheet.
Bake for 45-60 minutes, until a knife is easily inserted in the center without much resistance (the exact time depends on how thin or thick the sliced potatoes are.)
Melt 2 tablespoons butter and mix with 1/4 cup panko breadcrumbs, 1/4 cup Parmesan, and 1 teaspoon fresh chopped thyme.
Remove the foil and evenly sprinkle the breadcrumb mixture over the top. Place back in the oven and bake, uncovered, until the crumbs are golden brown.
Let rest 10 to 15 minutes before cutting. This gives the cream sauce time to settle and thicken a bit and will make it easier to serve.

Notes

If you’ve got a mandolin for the potatoes, it’s way faster/easier!

Nutrition

Nutritional information given is an automatic calculation and can vary based on the exact products you use and any changes you make to the recipe. If these numbers are very important to you, I would recommend calculating them yourself.

Other Notes

Course: Side Dish

Cuisine: American

Overhead view of a dish of yukon gold and sweet potato gratin

Serving Suggestions

This sweet potato and Yukon gold gratin makes a stunning side during the holidays or any special occasion dinner. It’s a great side for Christmas or Easter ham and Thanksgiving turkey but also dishes like bacon wrapped pork tenderloin or honey glazed salmon anytime.

How To Store & Reheat Leftovers

Fridge. Store leftover Yukon and sweet potato gratin in the fridge for up to 3 days. You can cover the baking dish tightly with foil or plastic wrap or transfer leftovers to an airtight container.
Reheat. Reheat the entire baking dish in the oven, covered with foil, until heated through. You can also reheat individual servings in the microwave.

More Potato Dishes To Try

I hope you love this delicious and easy recipe – be sure to give it a review below! Also don’t forget to follow Belly Full on TikTok, Instagram, Facebook, Pinterest, and YouTube!

Serving a slice of Yukon gold and sweet potato gratin