Easy sweet potato dauphinoise or sweet potatoes au gratin with Parmesan and lots of spices is a comforting side dish or light main meal for any time of the year.
This sweet potato dauphinoise is one of my favorite side dishes - perfect for Thanksgiving or Christmas, for instance! This Savory Sweet Potato Pie is also perfect for the holidays.
This time, I tried something different: a flavorful Parmesan sweet potato gratin. Layers of meltingly soft potatoes are spiced with cinnamon, cumin, and turmeric. This garlicky and cheesy dish is perfectly suited as a side for chicken or fish.
This gratin works as a main dish, too. I reheated the leftovers the next day and made a crisp green salad with Yogurt Dressing, and I couldn't have been happier. A satisfying, light, and super healthy lunch!
Ingredients: 10 | Prep Time: 20 minutes | Cook Time: 50 minutes | Servings: 4 | Difficulty: Easy
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Recipe ingredients
Dairy: I use a mix of milk and cream for this gratin. You can use only cream if you prefer, but using only milk won't work - the dish will turn out too runny. The combination gives the gratin a creamy texture without being overly rich.
Sweet potatoes used for potato gratin should be sliced very thinly and regularly. Otherwise, it will take them ages to cook.
- It is very advisable to use a mandoline; it makes the job much better and faster than you could possibly do it yourself. I tried many times (before buying a good mandoline) to cut potatoes thinly, but it never really worked out.
- You don't need a mandoline to make these Baked Sweet Potato Slices.
Parmesan: Choose a vegetarian hard cheese if you like to keep this dish vegetarian.
See the recipe card for full information on ingredients and quantities.
How to make sweet potato dauphinoise?
Step #1: Slice the sweet potatoes very thinly using a mandoline or a sharp chef's knife.
Step #2: Mix them with the oil and spices.
Step #3: Mix heavy cream and milk in another bowl.
Step #4: ย Pour โ of the liquid mixture into the baking dish. Arrange ยฝ of the potatoes in the dish.
Step #5: Sprinkle them with ยฝ of the Parmesan.
Step #6: Addย another โ of the milk-cream mixture and arrange the remaining sweet potato slices on top. Pour in the remaining liquid.
Step #7: Pushย the sweet potatoes a little bit down so that the liquid surrounds them. Sprinkle with the remaining Parmesan.
Step #8: Bake for 40-50 minutes until golden brown and set.
How to season the sweet potatoes?
I used a mixture of cinnamon, turmeric, cumin, cayenne pepper, and garlic, a rather Middle East-inspired spice mixture.
But this spice mixture is really optional; you can spice the dish with any kind of spices you like, something to better fit your personal taste, or something to fit the main dish you're serving this gratin with.
Salt and pepper would be quite enough as well if you like to keep it simple; the tubers have enough taste on their own.
Otherwise, I sometimes like to spice the dish with paprika, either sweet, hot, or smoked, dried herbs like thyme, savory, or oregano, and even herb mixtures like Herbs de Provence or Italian Herbs. Just follow your inclination; I think you can hardly go wrong here.
More seasoning ideas for any sweet potato dish
- smoked paprika, black pepper, cayenne pepper, salt, a little brown sugar, and some oil
- Italian seasoning, salt, some olive oil, and oregano or rosemary
- cinnamon and brown sugar for a sweeter version of roasted sweet potato wedges
- cumin, garlic powder, sweet paprika, black pepper, salt, and some oil
- sumac, garlic, salt, and olive oil
- Use any of these ideas to season Pan-Fried Sweet Potatoes.
Store and reheat
Refrigerate: Let the sweet potato dauphinoise cool completely, then cover the dish or transfer the leftovers to an airtight container. It keeps well in the fridge for 3-4 days.
Reheat in the oven at 350ยฐF/180ยฐC until hot throughout (about 15-20 minutes). Cover with foil so the top doesn't darken too much. You can also reheat individual portions in the microwave, but the texture is best when warmed in the oven.
I don't recommend freezing this dish; the creamy mixture can separate once thawed, and the texture won't be as smooth.
How to serve?
The sweet potato dauphinoise serves two as a main dish with a salad or four as a side dish. The gratin is at its best when served immediately, but it can be reheated in the oven as well. It doesn't freeze well.
Other delicious bakes
And just in case you are seeing this recipe around Thanksgiving, have a look at these 10 Thanksgiving Potato Side Dishes.
Do you like this recipe?
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Sweet Potato Dauphinoise
Equipment
- Medium baking dish
- Bowls
Ingredients
- 1 lb sweet potatoes Note 1
- ยฝ teaspoon cinnamon
- ยผ teaspoon cumin
- โ teaspoon cayenne pepper
- ยฝ teaspoon turmeric
- 3 garlic cloves
- 1 tablespoon olive oil
- ยฝ cup whole milk Note 2
- 1ยฝ cup heavy cream
- ยฝ cup Parmesan freshly grated
- a small knob of butter
- fine sea salt
Instructions
- Preheat the oven to 400ยฐF/ 200ยฐC.
- Slice sweet potatoes: Peel the sweet potatoes and slice them thinly using a mandoline. Place them into a bowl.1 lb sweet potatoes
- Seasoning: Mix cinnamon, cumin, cayenne pepper, turmeric, grated garlic, and olive oil. Rub the sweet potato slices with this mixture.ยฝ teaspoon cinnamon + ยผ teaspoon cumin + โ teaspoon cayenne pepper + ยฝ teaspoon turmeric + 3 garlic cloves + 1 tablespoon olive oil
- Mix milk and cream, and add a little salt to the mixture.ยฝ cup whole milk + 1ยฝ cup heavy cream + fine sea salt
- Assemble the dish: Butter a casserole dish. Place about โ of the milk-cream mixture into the dish. Arrange half of the potato slices in the dish. Sprinkle them with half of the grated Parmesan.ยฝ from ยฝ cup Parmesan
- Add another โ of the milk-cream mixture and arrange the remaining sweet potato slices on top. Pour in the remaining milk-cream mixture.
- Push the potatoes a little bit down to make sure that the liquid surrounds them. Then, sprinkle with the remaining Parmesan. Dot with butter.a small knob of butter
- Bake for about 40-50 minutes or until the sweet potatoes are soft. If the gratin gets too brown too soon, cover it loosely with aluminum foil.
- Rest for 5-10 minutes before serving.
Notes
- Servings: The recipe serves two as a main dish and 4 as a side dish.
- Dairy: A mix of milk and cream works best. You can use all cream, but all milk will make the gratin too runny.
Stephanie says
Why does it look curdled?
Carol says
If anyone would actually make this recipe you would realize that the photos show a lovely casserole with the sweet potato slices adding texture in layers. It is a bit difficult to make sweet potato look really gorgeous so what I am seeing is a beautiful dish to try and curdled???? No.I have made this -it takes time and it is really really delicious. For sweet potato fans!
Adina says
Hi Carol. Thank you for the nice comment. I am so happy you tried this recipe and that you liked it.
mjskitchen says
YUMMMY!!! Fabulous idea to use sweet potatoes in a gratin. It looks fabulous and I love your seasoning.
Kim says
All hail the sweet potato. I did not know that they were not readily available in Europe until recently. The gratin looks amazing and I love how you added a little turmeric to the spices. A great dish!
Sissi says
I must admit I'm also not a huge fan of sweet potatoes, but your gratin looks so gorgeous I'd be more than happy to taste it an check if I haven't changed my mind ๐
Priya @priyascurrynation says
potato + parmesan = what a creaaammmmyyyyy combo ! I love this recipe...
Marvellina | What To Cook Today says
I love the natural sweetness of sweet potato and then the savory cheese...perfect combo!
Evi @ greenevi says
(Sweet) potato gratin is the ultimate comfort food! This looks really great, Adina ๐