Easy sweet potato dauphinoise or sweet potatoes au gratin with Parmesan and lots of spices, a comforting side dish or light main meal for any time of the year.
I adore sweet potatoes! Honestly, they are for me one of the most comforting vegetables out there, so soft and tender, sweet, and delicious! And this sweet potato dauphinoise is one of my favorite side dishes. Something perfect for Christmas, for instance!
This time I have tried something different. A flavorful Parmesan sweet potato gratin, layers of meltingly soft potatoes, spiced with lots of spices like cinnamon, cumin, and turmeric, a garlicky and cheesy dish perfectly suited as a side for chicken or fish.
And not only a side dish. I reheated the leftovers the next day, made a crisp green salad with yogurt dressing and I couldn’t have been happier. A satisfying, light, and super healthy lunch!
About the ingredients
- I used a mixture of milk and cream to pour over the gratin.
- Many people only use the cream for making a potato gratin or dauphinoise, but to tell you the truth, although I love those creamy gratins, I am usually not so keen on eating so much cream (unless is whipped and on a cake… 🙂 ).
- Other people only use milk for their gratins and I tried that myself a couple of times. It is not that I did not like it at all, but still I prefer the creamier result given by the combination of milk and cream.
- And the Parmesan is a must! Choose a vegetarian hard cheese if you like to keep this dish vegetarian, but don’t leave it out, it was so good, it added just that amount of cheesiness and goodness those potatoes needed.
All potatoes, either sweet or regular, 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 (Amazon affiliate link), 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.
How to season sweet potatoes?
- I used a mixture of cinnamon, turmeric, cumin, cayenne pepper, and garlic, a rather Middle East-inspired spice mixture. It was absolutely amazing.
- 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, even herb mixtures like Herbs de Provence or Italian Herbs. Just follow your inclination, I think you can hardly go wrong here.
More suitable spice mixtures, great for soups, chilies, stews, or 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
How to serve?
The dish 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 gratins or casserole:
- Pumpkin Potato Bake
- Dairy-Free Green Bean Casserole
- Tortellini Vegetable Bake
- Kirschmichel – Cherry Casserole
- Cauliflower Feta Bake
And just in case you are seeing this recipe around Thanksgiving, have a look at these 10 Thanksgiving Potato Side Dishes.
Sweet Potato Dauphinoise
- 1 lb sweet potatoes 450 g
- ½ teaspoon cinnamon
- ¼ teaspoon cumin
- 1/8 teaspoon cayenne pepper
- ½ teaspoon turmeric
- 3 garlic cloves
- 1 tablespoon olive oil
- 1 cup milk 250 ml
- 1 cup heavy cream 250 ml
- 1/2 cup Parmesan 50 g
- a small knob of butter
- fine sea salt
- Preheat the oven to 200 degrees Celsius/ 400 degrees Fahrenheit.
- Slice sweet potatoes: Peel the sweet potatoes and slice them thinly using a mandoline. Place them into a bowl.
- Seasoning: Mix cinnamon, cumin, cayenne pepper, turmeric, grated garlic, and olive oil. Rub the sweet potato slices with this mixture.
- Mix milk and cream, add a little salt to the mixture.
- Assemble the dish: Butter a casserole dish. Place about 1/3 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.Add another 1/3 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.
- 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.