Vegan Sweet Potato Gratin
Garlicky sweet potatoes. Cashew oat cream sauce. A crunchy walnut-sun-dried tomato topping. Combined and baked all together into this cozy baked sweet potato gratin recipe! So simple and a fantastic side-dish for a holiday table. And *drum roll* it's healthy! Shocker, I know. ;)
This recipe is:
Vegan and gluten free.
Easy to make. Slice and arrange the sweet potatoes. Blend the sauce. Combine. Bake. DONE.
A real crowd-pleaser (kids love it!).
Creamy and cheesy.
Healthy enough for weeknight dinners.
Great for leftovers and meal-prep.
Amazing as a Thanksgiving side!
This sweet potato gratin features Oatly Barista Edition Oat Milk as the base for a “white sauce.” Classic gratin recipes generally feature butter, cream and a cheese like gruyere. So when I was coming up with this recipe I knew I wanted to develop a sharp, cheesy cream sauce with a lot of richness.
I achieved that using oat milk, cashews, nutritional yeast and miso paste. The resulting sauce is a snap to make. And -- when baked -- envelops the sweet potatoes in a blanket of cheesy, velvety goodness.
So, let’s talk about oat milk for a second. It's no secret that I'm a super-fan of Oatly. I've loved them ever since I first got my hands on a box of their oat milk! Not exaggerating, I proselytize about it to everyone I know.
It's the food nerd in me. What can I say?
The thing that took my fandom over the top is how well their oat milks work as dairy substitutes in cooking. I’ve always had a tough time finding plant milks that work well for savory cooking. I usually use full fat coconut milk or homemade cashew milk. Both are great! But coconut can often be too, well, coconut-y. And cashew is rich enough, but doesn’t have the dairy-like flavor I’m obsessed with in oat milk.
I use Oatly oat milk as a 1-to-1 substitute in about any recipe that calls for milk or cream. I’ve used it in curries, chowders, bisques, creamy pasta sauces and so much more. The possibilities are endless.
Make this recipe deluxe by folding dairy-free cheese into the blended sauce. You can top the gratin with more "cheese" before baking. Or — if you’re like me, only omitting cow-dairy — you could shred goat cheddar over top for extra sharpness.
Vegan Sweet Potato Gratin Recipe
Prep time: overnight (to soak cashews) - Cook time: 50 mins - Makes: 8-10 servings
Notes: This can be made with Oatly barista blend OR Oatly full fat oat milk equally well.
4 medium-large sweet potatoes, sliced thinly into rounds
3 tbsp olive oil
3/4 tsp sea salt
1/2 tsp black pepper
3 cloves garlic, minced
1 cup soaked cashews (soaked 8 hours or overnight)
1 1/4 cup Oatly Barista Edition Oat Milk
1 tbsp white miso paste
3 tbsp nutritional yeast
2 tbsp apple cider vinegar
1/4 tsp turmeric powder (for color)
1/8 tsp smoked paprika
1/8 tsp salt + 1/8 tsp pepper + more to taste
1/2 cup walnuts, chopped finely
2 tbsp sun dried tomatoes, chopped roughly
Toss sweet potato slices in olive oil, 3/4 tsp sea salt, 1/2 tsp pepper and garlic until evenly coated. Arrange slices around the edges of a regular (~3 qt) rectangular baking dish, filling the center if the dish with more neatly arranged slices. Cover the dish with foil and bake at 425F for 40 mins until fork tender.
While the sweet potatoes are baking, make the “cream” sauce. In a high powered blender combine the cashews, oat milk, white miso paste, nutritional yeast, apple cider vinegar, turmeric powder, smoked paprika, 1/8 tsp salt and 1/8 tsp pepper. Blend on high until smooth and creamy — about 1 min 30 seconds. Set aside.
Once the sweet potatoes have finished roasting, remove the dish from the oven and pour the “cream” sauce over top — lifting the slices gently to get the cheese sauce between the slices.
Toss walnuts and sun dried tomatoes together. Spread over top of the gratin evenly.
Bake again for 10 mins at 425F and serve warm. Enjoy!
This post is sponsored by Oatly. All words and opinions are my own. Thank you for supporting the sponsors that make this site possible!