Smoky Maple Vegan Sweet Potato Gratin

Created by Laura Wright
5 from 9 votes
This vegan sweet potato gratin has richness from a savoury and sweet homemade cashew "cream" that features maple syrup, nutritional yeast, onion powder, Tamari, liquid smoke, garlic, and raw cashews. So deeply flavourful and the bubbly and browned top is gorgeous with a spiral pattern and minced fresh thyme.
An up close, overhead shot shows a vegan sweet potato gratin in a ceramic baking dish. The top is broiled and browned in spots.

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.

An overhead shot shows a vegan sweet potato gratin in a ceramic baking dish. The top is broiled and browned in spots. A brass serving spoon is nearby.
An overhead shot shows peeled sweet potatoes on a worn wood cutting board.

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.

An overhead shot shows a hand using a silicone pastry brush to distribute a cashew "cream" mixture over baked sweet potato slices in a dish.
An overhead shot shows a vegan sweet potato gratin in a ceramic baking dish. The top is broiled and browned in spots. A brass serving spoon is sticking out of the gratin.
An up close shot shows a spoonful of gooey vegan sweet potato gratin with a few thyme leaves on top.

Smoky Maple Vegan Sweet Potato Gratin

This vegan sweet potato gratin has richness from a savoury and sweet homemade cashew "cream" that features maple syrup, nutritional yeast, onion powder, Tamari, liquid smoke, garlic, and raw cashews. So deeply flavourful and the bubbly and browned top is gorgeous with a spiral pattern and minced fresh thyme.
5 from 9 votes
An up close, overhead shot shows a vegan sweet potato gratin in a ceramic baking dish. The top is broiled and browned in spots.
Prep Time: 15 minutes
Cook Time: 50 minutes
Total Time: 1 hour 5 minutes
Servings 6 -8

Ingredients

  • 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

Notes

  • 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!

Instructions

  • 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.
03/11/2023
Posted in: autumn, cashews, creamy, gluten free, grain-free, holidays, roasted, salty, side dish, smoky, sweet, sweet potatoes, umami, vegan, winter

11 comments

Recipe Rating




  • Dawn

    5 stars
    I made this using 3/4 tsp of smoked paprika instead of liquid smoke, as Laura suggested. And I dipped each slice into the cashew cream to ensure they were all evenly coated. It was perfect! Such great flavors, and even the picky eaters enjoyed it! The leftovers are equally good reheated or cold out of the fridge (or even adorning plain vegan yogurt and granola). Thanks for another great recipe!

  • Daniela Ahlenius

    5 stars
    I loved this recipe and today for Thanksgiving I am making it for the second time! I appreciate that it is so easy to make, specially when you prep the day before by cutting the sweet potatoes. I substituted the nutritional yeast with half a tablespoon bicarbonate and half a tablespoon of lemon and it worked really well. Since the liquid smoke is not so healthy for us I switched it out for a little bit of chipotle (not too much) and it worked out really well.

    Happy cooking everyone!

  • Elizabeth

    Hi Laura,
    I’m planning on making this dish for American Thanksgiving this week. I’m wondering if you think it’s possible to use smoked paprika in place of the liquid smoke. I’m really trying to use what I have on hand when I’m able and thought it might work, but wanted to get your input. Thank you for all you bring to this site!

    • Laura Wright

      Hi Elizabeth!
      Smoked paprika would be great in this recipe. I would add 3/4 teaspoon to step 2, just blending it in with the cashew “cream.” Hope you love it!
      -L

  • Samira

    5 stars
    We made this dish tonight and it was absolutely fantastic. I accidentally sliced my sweet potatoes a little too thinly, but it still worked out perfectly fine. Just needed some earlier checking in with regards to baking time. Will do this again for Christmas this year :-)

    Thank you so much, Laura!

    • Laura Wright

      So glad that you enjoyed in Samira!!
      -L

  • Karen

    It’s the first time that I can’t read the recipe because there are too many ads :(
    I click to make them disappear and they bounce right back.
    Very very frustrating. At least I can read the ingredients so I will wing it!

    • Laura Wright

      Hi Karen,
      I’m so sorry about this. I will check in with the ad provider to see what we can do. In the meantime, if you click on the “print recipe” button on any of my posts/recipes, an ad-free version of the recipe will pop up in another tab. Here’s the link for this one: https://thefirstmess.com/wprm_print/28289
      -L

  • Colleen

    Is it possible to make this nut free? Could I use coconut milk?

    • Laura Wright

      Hi Colleen,
      I would replace the cashews and water with 1 3/4 cups of unsweetened oat or soy milk. Just pour that into the blender and blend with the nutritional yeast, olive oil, onion powder, garlic, maple etc.
      -L

  • Elizabeth

    What a beautiful dish! I think this one is going on my Thanksgiving menu. Yum!