Sweet Potato Gratin is a healthier alternative to traditional potatoes au gratin; scalloped sweet potatoes layered between vegan béchamel sauce, baked to creamy perfection. Enjoy this Whole30 approved side dish for casual family dinners and holiday meals.
Vegan Sweet Potato Gratin
Sweet Potato Gratin is a warm and comforting dish that is perfect for cooler months, especially around the holidays. It’s warm, hearty, and a great comfort meal, even without the heavy cream and cheese.
When I first made this decadent, cheesy side dish, I made a regular béchamel sauce, filled with butter, cream, and flour; all the things that currently don’t work for my family’s gut health. So I spent time tweaking the recipe until I created the perfect tummy troubles-free recipe to share with you.
Why You’ll Love This Sweet Potato Gratin Recipe
- Healthy Alternative to Potato au Gratin: This vegan sweet potato gratin recipe is also Whole30 compliant, paleo-friendly, and gluten-free. Swap russet potatoes for sweet potatoes, heavy cream for full-fat coconut milk, gruyere cheese for cashew-based cheese, and all-purpose flour for gluten-free flour. We still have the rich, herby flavors of the classic dish!
- Great for Gatherings: Whether it’s a potluck, Thanksgiving, or even brunch, this is a versatile dish that you can serve on any occasion. At gatherings, it can be tough to find dishes that everyone can enjoy, no matter their dietary needs or preferences. But everyone can indulge in this healthy sweet potato gratin.
- Ultimate Fall Dish: I love sweet potatoes year-round but when the cool weather kicks in, it’s a staple in my recipes. It makes for a hearty, cozy dish that fills you up. Add fresh nutmeg for a warm touch of spice, and this recipe becomes the side dish of the season!
What is Gratin?
Gratin, or au gratin, is a French culinary technique. A gratin dish includes an ingredient, usually sliced vegetables, meat, or fish, topped with a browned crust, often made from breadcrumbs, grated cheese, eggs, or butter. The dish is then baked or broiled until the top is golden brown and crispy.
“Gratin” comes from the French word “gratter,” which means “to scrape” or “to grate,” referring to the technique of grating cheese or breadcrumbs over the top of the dish before baking. Gratin dishes are popular in many cuisines around the world and can vary widely in ingredients and flavors.
Ingredients for Sweet Potato Gratin
Making a vegan side dish doesn’t have to be hard. I’ve found the best replacements for common ingredients so you can make a vegan sweet potato gratin that is just as satisfying as the classic recipe!
- Sweet potatoes: I like to use assorted colors for my sweet potato gratin as it makes for a more ornate dish on the holiday table. Peel and thinly slice them.
- Coconut oil: This is the base of your sauce. It has a mild flavor and a high smoking point.
- Cashew milk and Full fat coconut milk: This lends creaminess to the vegan sauce.
- Cassava flour: Do you cook with cassava flour? This thickens the “cheese sauce.” It’s one of the few gluten-free thickeners that really act like wheat flour. It creates the best sauces and gravy, without an altered taste.
- Seasoning: Vegan doesn’t mean no flavor! I use granulated onion or onion powder, granulated garlic, freshly grated nutmeg, paprika, salt, and black pepper.
- Fresh parsley: Chop it up finely. You can also substitute this fresh herb with 1 tablespoon of parsley flakes.
- Freshly grated nutmeg: This brings the cozy flavors of fall into this dish. It has a nutty, warm quality.
- Nutritional yeast: This provides a cheesy taste without the actual cheese. Use this to season the sauce.
See recipe card for quantities.
Sweet Potatoes for Sweet Potato Gratin
For this sweet potato gratin recipe I used two kinds of sweet potatoes, golden/white sweet potatoes and regular sweet potatoes. You may use only one kind of sweet potato if you like or only have access to one variety of sweet potatoes.
I prefer to slice my sweet potatoes really thin. I used a mandolin slicer to slice the sweet potatoes into even slices. Do you have a mandolin slicer? They are really great for meal prepping. Get one here.
How to Make Sweet Potato Gratin
Making the Vegan and Gluten Free Béchamel Sauce
To make the vegan and gluten free béchamel sauce, I used coconut oil, coconut milk, almond milk and cassava flour.
To bring out the flavor of the sauce, season it with fresh herbs and some spices. You can even add some sautéed mushrooms and caramelized onions to the sauce.
Adding a bit of nutritional yeast, also gives it more of a “cheesy” flavor and is the perfect addition to this recipe. Do you use nutritional yeast in your cooking? Want to learn more about nutritional yeast and how to use it, then click here.
Look at how thick and creamy this sauce is. Can you tell that it is vegan? I certainly can’t. When the sauce is at the desired consistency I remove the sauce from the heat and then add my seasoning.
Layering the Sweet Potato Gratin
Layer your sweet potatoes however you choose. I start with some sauce at the bottom, then a layer of potatoes, then repeat until I’ve used up all your sauce and potatoes.
When I am not in a rush I get a bit fancy and make my top layer into a flower. To make the flower, start at the center of your baking dish, then make a circle with the sweet potato slices. Then tuck slices of sweet potatoes under each layer of circles until it looks like a blooming flower. To create a bit of contrast don’t cover the top completely with the flower.
Storage
Once the dish has completely cooled, transfer leftovers into an airtight container in the fridge for up to 5 days. Reheat leftovers in the microwave.
Tips for the Best Sweet Potato Gratin
- You may use 1/2 lb of regular sweet potatoes mixed with 1/2 lb of golden sweet potatoes to add some color contrast to the dish.
- If you don’t have a problem with gluten you can substitute the cassava flour for regular flour. After you’ve melted the coconut oil in a hot pan, sprinkle the flour into the pan and mix together. Cook for 2-3 minutes then add the coconut milk and almond or cashew milk.
- Monitor the sweet potato gratin as it bakes. If it appears to be browning too quickly, cover it with aluminum foil.
Frequently Asked Questions
Although the two terms are often used interchangeably, they do reference different things. Gratin is a culinary technique whereas “au gratin” refers to the browned crust on top of a dish. Therefore, all dishes described as “au gratin” are gratins, but not all gratins are necessarily described as “au gratin.”
While both scalloped potatoes and potato gratin involve thinly sliced and layered potatoes baked in a dish, the main difference lies in the texture and topping. Scalloped potatoes are creamy and may not have a crispy crust, whereas potato gratin has a crispy, golden-brown crust on top due to the gratin technique. Also, potato gratin typically contains cheese and scalloped potatoes do not.
This dish pairs really well with a side of Sautéed Spinach.
Sweet Potato Gratin
Equipment
- Saucepan
- Whisk
- Quiche Pan
Ingredients
- 2-3 lbs sweet potatoes peeled and thinly sliced
- 2 tablespoons coconut oil
- 1 cup full fat coconut milk
- 1 cup almond or cashew milk
- 2 tablespoons cassava flour
- 1 tablespoon granulated onion or onion powder
- 1 teaspoon granulated garlic
- 1/4 cup fresh parsley chopped; may substitute with 1 tablespoon of parsley flakes
- 1 teaspoon salt
- 1/4 teaspoon black pepper
- 1 teaspoon of freshly grated nutmeg
- 2 tablespoons nutritional yeast
- pinch smoked paprika
Instructions
- Preheat the oven to 350 °F
- Add the coconut oil to a saucepan on medium heat and bring up to temperature
- When the oil is hot and melted, add the coconut milk and the almond or cashew milk
- Bring up to temperature them whisk in the cassava flour
- Reduce the heat to medium-low and continue to cook until the sauce is thick and coats the spoon
- Then remove the sauce from the heat and add the granulated onions, granulated garlic, parsley, salt, black pepper, nutritional yeast and nutmeg. Use a whisk to mix together the ingredients for a really smooth sauce
- Spray a large quiche pan with cooking spray, then add about 1/4 cup of sauce to the bottom of the pan
- Next, add a layer of sweet potato slices, then top with another 1/4 cup of sauce. If you are using two kinds of sweet potatoes you can alternate the colors when layering
- Continue to layer until all your sauce and potatoes have been used. Do not add sauce to the top layer
- Spray the last layer of sweet potatoes with cooking spray, then sprinkle with a light dusting of smoked paprika
- Place sweet potato gratin on middle shelf of oven and bake for 45 minutes or until the potatoes are fork tender
- Then remove from the oven and allow to cool for about 15 minutes before serving
Nutrition
The information listed in the recipe card is an estimate provided by an online nutrition tool. The tool evaluates ingredient names and amounts then makes calculations based on the number of servings listed for the recipe. It is provided as a general guideline and not as a precise calculation. For precise nutrition information please feel free to add the ingredients to your preferred nutrition calculator or consult a doctor or licensed nutritionist.
Sally McGuire Says
Wonder how the mac n cheese would come out without the egg? I’m allergic, which throws a big wrench into most Whole30 recipes.
Rowana Says
This looks very very yummy, i’m going to make this and post my dish for you to see.
Metemgee Says
Can’t wait to hear how it comes out!