This sweet potato au gratin features tender sweet potatoes in a rich cream sauce with lots of gouda, gruyere, and Parmesan cheese baked on top.
If you’re looking to stray away from the usual sugary sweet potato casseroles this year, you’ve got the perfect alternative staring you in the face!
Traditional au gratin potatoes use regular potatoes, but today we’re giving this beloved side dish classic a cheesy sweet potato twist.
And it is nothing short of legendary.
Turns out a little creamy sauce action plus three kinds of cheese is just heavenly when paired with sweet potatoes. Totally shocking, I know.
This Sweet Potato Au Gratin features…
- Perfectly tender sweet potato slices.
- A rich cream sauce.
- Gooey gruyere, gouda, and Parmesan cheeses.
Making the Sweet Potato Au Gratin
(scroll down to the bottom of the post for the full recipe)
Ingredients You Will Need
- Sweet potatoes
- Heavy whipping cream
- Gruyere cheese
- Gouda cheese
- Parmesan cheese
How to Prepare Sweet Potatoes
Start by peeling the sweet potatoes and then use either a knife or mandoline to thinly slice into 1/8″ slices.
For a time-saver, you can peel and slice the sweet potatoes ahead of them and soak them in water in the fridge up to 2 days in advance. Pat sweet potatoes dry before proceeding with recipe.
Tips for Perfect Au Gratin Potatoes
- Overlap sweet potatoes in pan – a little bit of overlap is totally fine when arranging the sweet potatoes in the pan. Do your best to make them all fit.
- Pour cream mixture over sweet potatoes – make sure sauce evenly coats every sweet potato slice for best results!
- Cover top with cheese – we recommend manually shredding the cheese yourself for best results.
- Bake au gratin uncovered – this helps the cheese brown super nicely!
- Allow au gratin to sit 10 minutes before serving – this helps the potatoes set up a bit.
Try these ideas for a different spin on these sweet potatoes!
- Try different cheeses – sharp cheddar, mozzarella, asiago, or Monterey jack would be great substitutes for the suggested cheeses!
- Add meat – a little crumbled bacon or prosciutto would be amazing topped on potatoes after baking.
- Use different fresh herbs – try a little fresh minced sage or rosemary in place of the thyme.
This is just pure indulgence in a pan, y’all. The sweet potatoes bake up SO perfectly tender and are absolutely smothered in rich, creamy sauce and tons of gooey cheese.
Forget the turkey, THIS is what you want to be digging into!
Save this recipe using the ‘save to recipe box’ button below. If you make it, please let us know! Leave a comment + star rating below, or take a photo and tag it on Instagram with #wholeandheavenlyoven.
A few more side dishes to add to your holiday dinner menu!
- Baked French Onion Gnocchi
- Caramelized Onion Green Bean Casserole
- Pan Fried Potatoes with Caramelized Onions
Three Cheese Sweet Potato Au Gratin
- 1-1/2 lbs sweet potatoes, peeled and very thinly sliced
- 1-1/2 cups heavy whipping cream
- 1/4 teaspoon ground nutmeg
- 1 teaspoon minced fresh thyme
- 1 teaspoon kosher salt
- 1/2 teaspoon ground black pepper
- 1/2 cup shredded gruyere cheese
- 1/2 cup shredded gouda cheese
- 1/4 cup grated Parmesan cheese
- Additional minced thyme for topping
- Preheat oven to 375F. Lightly grease an 8×8 inch square baking pan.
- Arrange sweet potatoes in baking pan, slightly overlapping to make them all fit. In a medium bowl, whisk heavy cream, milk, nutmeg, thyme, salt and pepper until smooth.
- Pour cream mixture evenly over sweet potatoes and top with cheeses. Bake au gratin at 375F 30-35 minutes until sweet potatoes are tender and top is lightly browned.
- Top au gratin with additional thyme and allow to sit 10 minutes before serving warm. Enjoy!