In this gorgeous, cheesy sweet potato side dish, layers of sweet potatoes and gold potatoes are bathed in rich, garlicky cream, topped sharp Gruyere and Parmesan cheeses and baked until fork tender in a Rosemary pie crust. An easy recipe with stunning results, this Sweet Potato Gratin is sure to be your new favorite holiday go-to!
Hearty and cozy comfort food meets a little rustic elegance in this simple twist on the classic potato au gratin casserole! Premade roll-out pie crusts and a mandolin slicer make prep work easy. Yes, there is a bit of a bake time. But the end result is absolutely worth it!
Subtly sweet, deeply savory and tender, these cheesy potatoes in a golden flaky crust will be your new tradition for holiday dinners and a to-die-for addition to your brunch menu!
What Is Gratin?
Gratin and Au Gratin potatoes refer to the same dish. Au Gratin is French literally means by grating. A gratin is a layered dish of thinly sliced potatoes baked with of grated cheese, heavy cream and topped with more grated cheese and sometimes a crust of bread crumbs.
This Sweet Potato Gratin recipe amps up the traditional idea of a top crust by baking the whole gratin in an easy pie crust infused with Rosemary and more cheese!
What is The Difference Between Scalloped & Gratin Potatoes
Scalloped Potatoes are baked in a rich cream sauce, often layered with thinly sliced onions and do not have a top crust of cheese or bread crumbs. However, my Ultimate Scalloped Potatoes recipe adds a little cheese to the cream sauce and layers for a best of both worlds kind of cheesy potato dish!
I’ll walk through an overview of ingredients & steps in this section along with helpful tips!
Look for specifics at the end of the post in the recipe card.
Ingredients for This Sweet Potato Gratin Pie
- refrigerated, roll-out pie crusts
- sweet potatoes
- Yukon gold potatoes
- gruyere cheese (or sharp white cheddar)
- shaved Parmesan cheese
- heavy cream
- fresh Rosemary
- salt & coarse ground pepper
How to Make Sweet Potato Gratin
Make the Easy Rosemary Crust. Unroll the pie crusts and sprinkle ⅓ cup of the cheeses, the fresh Rosemary and black pepper over one crust. Top it with the second crust. Use a rolling pin to roll crusts out to 13 inches and seal edges together.
Press the Rosemary crust into the bottom and up the sides of a 9 inch spring form pan. Place in refrigerator to chill while prepping the potatoes.
Add the Potato Layers. Layer peeled and sliced gold potatoes, sweet potatoes, salt and cheese in the crust to create 3 complete layers in the crust.
Top with Cream & More Cheese. Use the microwave to heat the cream and garlic. Pour the garlicky cream over the layers and top with the rest of the cheese.
Bake. Bake covered with foil at 450 degrees Fahrenheit for 1 hour. Uncover and bake for 15-25 more minutes.
Making This Recipe Ahead of Time
To get a jump on making this recipe, grate your cheeses and peel and slice your potatoes the day before. Store cheeses together in a zip top bag, but store potatoes separately in bags. This eliminates almost all of the prep time
Storing It In The Fridge
Store any leftover Sweet Potato Gratin covered in the refrigerator for 3-4 days. The crust will get soft on the bottom the longer the gratin sits. Because of the cream and cheeses, this recipe does not freeze well.
Tips For Making the Best Sweet Potato Gratin
- Use a mandolin slicer to ensure that potatoes are sliced thinly and evenly (⅛ inch-¼ inch thick). Thin, consistent slices enables your potatoes cook evenly throughout the whole dish to fork tender goodness in the time allotted.
- Don’t forget to cover the Sweet Potato Gratin with foil during the first stages of its cook. The foil keeps it from overbrowning, BUT IT ALSO traps steam in the dish to help cook the potatoes.
- Letting the Gratin rest after baking allows it to firm up and makes it much easier to slice.
- Placing a baking sheet under the springform pan as your gratin bakes will catch any spills that could happen while your Sweet Potato Gratin bakes, keeping your oven clean!
What To Serve with Sweet Potato Gratin
This cheesy sweet poato side dish is an ideal addition to all your holiday favorites. But it is just as delicious next to a seared cast iron skillet steak and a pile of Parmesan Brussel Sprouts. Try it with Louisiana Dirty Rice and a green salad for a pure comfort food meal.
- Southern Chicken & Dressing
- Cranberry Bacon Walnut Stuffed Pork Tenderloin
- Creamy Green Bean Casserole (without canned soup)
More Sweet Potato Recipes You’ll Love
- Sweet Potato Casserole with Pecans
- Sweet Potato Casserole with Marshmallows
- Fluffy Mashed Sweet Potatoes
- Stuffed Sweet Potatoes with Cranberries, Spinach and Goat Cheese
- Parmesan Sweet Potato Wedges
- Taco Stuffed Sweet Potatoes
If You Love Sweet Potatoes & Have Made This Recipe, Give It All The Stars & Leave A Fun Comment! I Love Hearing From You!
Sweet Potato Gratin with Rosemary Crust
- 1 package refrigerated, roll out pie crusts (2- 9 inch crusts)
- 1 tablespoon chopped fresh Rosemary
- ¼ teaspoon coarse ground black pepper
- 1 ⅔ cups grated Gruyere cheese (or sharp white cheddar)
- ⅓ cup shaved Parmesan
- 1 ½ pounds sweet potatoes
- 1 ½ pounds Yukon gold potatoes
- 1 teaspoon salt
- ⅔ cup heavy cream (or half & half cream)
- 1 teaspoon minced garlic
- Preheat oven to 450° Fahrenheit. Toss cheeses in a bowl together and set aside.
- Unroll pie crusts on a lightly floured surface. Sprinkle ⅓ cup of the mixed cheeses, chopped Rosemary and black pepper over one crust. Top with second crust. Use a rolling pin to roll crusts out to 13 inches and seal edges together.
- Place Rosemary crust in a 9 inch spring form pan. Press in bottom and up the sides of the pan. Fold down any excess edges to make crust even with the top of the pan. Place in refrigerator to chill while prepping the potatoes.
- Peel sweet potatoes and gold potatoes. Use mandolin to slice all of the potatoes evenly and thinly (⅛-1/4 inch thick).
- In bottom of crust, begin to layer ⅓ of the sliced gold potatoes and then ⅓ of the sliced sweet potatoes. Sprinkle with ⅓ of the salt and ⅓ cup of mixed cheeses. Repeat these layers 2 more times to make 3 complete layers in the crust. Press layers down if needed so they fit beneath the top of the pan.
- Heat garlic and cream in a glass measuring cup for 45 seconds in the microwave. Stir well and pour over top of your cheesy layers. Top with rest of cheese. Cover with aluminun foil and bake in preheated oven for 1 hour.
- Remove foil and bake for an additional 15-25 minutes or until the crust is richly browned and the cream is bubbling around the edges and in the middle of the pie. Remove from oven and let rest for 10-15 minutes. Move to serving plate or cake pedestal. Remove outer ring. Garnish with additional Rosemary, if desired.