Vegan sweet potato gratin is easy to make and looks kind of fancy! This cozy baked recipe combines thinly sliced sweet potatoes, homemade cashew cream, spices, maple syrup, garlic, and fresh thyme for a soft bake with a perfectly caramelized and crunchy top. Coming together in about an hour, this festive vegan Thanksgiving recipe emerges from the oven tender and gorgeous. Serve warm, right out of the oven alongside other classic holiday veggie sides like olive oil mashed potatoes and roasted brussels sprouts.
I love a festive and healthy sweet potato gratin. The layers of thinly sliced sweet potato look so beautiful and impressive. But the whole thing is really easy to make. I slice the sweet potatoes with a mandolin to get the job done fast. I have you make an extremely well-seasoned savoury cashew cream to bathe the slices in. It’s got garlic, Tamari, onion powder, a bit of olive oil, liquid smoke and maple syrup.
The first few layers of the gratin, I just chuck into the dish (no need to be precious!). As I go, I layer the sweet potatoes with some of the cashew cream mixture, salt, pepper, and minced thyme. When I’m ready to do the final top layer, that’s when I take my time and make it extra pretty.
I will say that I am taking some liberties calling this a gratin! This dish technically falls into the “scalloped” category of lushly layered potato dishes because it has a creamy sauce in between the slices. Gratin refers to the presence of cheese between the layers as well. The nutritional yeast and Tamari do give a slight cheesy vibe, so hopefully you can forgive me with the naming of this fully plant-based side.
One thing that I find particularly key to the success of this vegan sweet potato gratin: try to source sweet potatoes that are all on the smaller side in terms of diameter–about 3 inches is ideal. The smaller slices in a concentric circle really make the finished top of the dish pop!
I hope you can find a little space for this one on your holiday table. The soft sweet potatoes with the bubbly browned top is just too good! More inspiration (including mains, appetizers, desserts, and salads) can be found in my roundup of vegan holiday recipes.
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Smoky Maple Vegan Sweet Potato Gratin
- ⅓ cup raw cashews, soaked for at least 2 hours and drained
- 1 tablespoon nutritional yeast
- 1 teaspoon onion powder
- 2 tablespoons maple syrup, plus extra
- 1 tablespoon olive oil, plus extra
- 1 teaspoon Tamari
- 1 clove garlic, peeled
- 3-4 drops liquid smoke
- 1 ½ cups water
- 4 small sweet potatoes (about 1 kilogram total)
- 1 tablespoon fresh thyme leaves, minced
- sea salt and ground black pepper, to taste
- It’s better to source sweet potatoes that are smaller in diameter if you can–about 3 inches is ideal.
- Fresh thyme is so, so good in this dish, but half the amount of dried thyme will also work.
- I only do the top layer in a pretty concentric circle! The layers leading up to it can be laid down into the baking dish without fuss.
- At certain points, it will seem like there’s too much liquid/”cream” in the baking dish. As it sits, it will settle and absorb!
- Preheat the oven to 400°F. Set out an 11-inch round or square baking dish.
- In an upright blender, combine the drained cashews, nutritional yeast, onion powder, maple syrup, 1 tablespoon of olive oil, Tamari, garlic, liquid smoke, and water. Blend on high until completely smooth and cream-like. Set aside.
- Peel the sweet potatoes. Using a mandolin slicer, slice the sweet potatoes about ⅛ inch thick.
- In a large bowl, toss the sweet potato slices with ⅓ cup of the cashew cream mixture.
- Once all slices are a bit wet and coated, start arranging one layer of slices in the baking dish. Sprinkle a bit of the minced thyme and some salt and pepper on top. Pour in a bit of the cashew cream mixture on top. Repeat this process until you have enough sweet potato slices for the top layer.
- I like to do the top layer in a pretty, concentric circle. Pour the remaining cashew cream mixture over top. Season with salt and pepper and finish with the minced thyme.
- Cover the dish tightly with foil and bake in the oven for about 30 minutes, or until the sweet potatoes are starting to become tender. Remove the foil, and use a pastry brush to distribute some of the cashew cream mixture all over the surface (it will have settled on the outer edges). Drizzle the top with olive oil, and bake uncovered for another 20 minutes, until browned on top. I like to pop it under the broiler for a minute or two to get extra colour.
- Straight out of the oven, drizzle a little bit of extra maple syrup over the top. Serve the sweet potato gratin hot. I like to garnish with some extra time leaves.