Dairy-Free Potato Gratin (Vegan Scalloped Potatoes)

This dairy-free potato gratin has a rich béchamel sauce made with cashews and miso, in place of the traditional milk/heavy cream.

Potatoes au gratin (pronounced “oh grah-TAN”, the French way) a.k.a. scalloped potatoes a.k.a. pommes dauphinoise (also French) are the ultimate comfort food for potato lovers. Layers of silky potatoes enveloped in a creamy, savory sauce, with a crisp golden top. It’s a super indulgent, très français way of cooking potatoes and always a crowd-pleaser.

Classic Julia Child-era gratin is made with milk and/or cream, butter, and lots of Gruyere cheese. But those of us who don’t cook with dairy can still make one as rich as the original – thanks to the mighty power of the humble cashew, as well as the combo of nutritional yeast and miso to recreate the “cheesy” flavor.

This dairy-free potato gratin is the perfect potato side dish for Thanksgiving and other holidays, as well as winter potlucks.

What’s In This Dairy-Free Potato Gratin

The star of this gratin is, of course, the sauce. This vegan béchamel is made with homemade cashew milk thickened with a roux (i.e. oil + flour cooked together). The béchamel is then flavored with fresh rosemary, garlic, nutritional yeast, miso, and a pinch of nutmeg. To finish the dish, you pour the sauce over thinly sliced Yukon Gold potatoes and top them with crunchy panko breadcrumbs.

Key Ingredients + Substitutions

• Cashews: Raw unsalted cashews create the creamiest sauce. (Blanched almonds work too). If you wanna skip making milk, you can experiment with store-bought unsweetened cashew milk or oat milk for the sauce. (Avoid almond milk – it can be overpowering.) However, the success of this dish will really depend on the specific brand, so try it and let me know how it goes! In my experience, cooked down store-bought plant milk can have a chemical aftertaste.
• Flour: For a gluten-free version, use a 1:1 GF flour.
• Nutritional Yeast: A “cheesy”-tasting seasoning sold in most supermarkets. Look for Bragg or Bob’s Red Mill brands. Lasts forever in the pantry so don’t hesitate to buy it if it’s your first time!
• Miso: This Japanese fermented soybean paste lends a savory “cheesy” flavor to this sauce and many other vegan dishes. It lasts forever in the fridge. If avoiding soy, double up on nutritional yeast in the sauce and compensate with an extra pinch of salt.
• Potatoes: Yukon Gold or white/butter potatoes work best here thanks to their waxy texture. Regular Idaho/russet potatoes are a bit too starchy for gratin, but will technically still work. For a fun twist, sub with sweet potatoes.
• Panko Breadcrumbs: Japanese-style, extra-crunchy ‘crumbs. Sold in most supermarkets.

How to Make Vegan Scalloped Potatoes

Find complete instructions with ingredient amounts in the recipe card below.

Step 1: Soak the Cashews.

In a blender, combine cashews with boiling water – but don’t blend yet – and set aside to soak for about 30 minutes. This softens the cashews so they can be blended into a creamy milk.

Step 2: Make Cashew Milk.

Blend until the nuts are completely pulverized, 1 to 2 minutes.

Step 3: Make the Sauce.

Heat a bit of oil in a medium pot and add flour. Cook, whisking almost constantly, until the mixture turns a pale blond color (this is called a roux). Then add the milk and whisk until the roux is fully dissolved. Bring to a simmer and cook gently until it’s thick enough to coat the back of a spoon (similar to the texture of crepe batter), 3 to 5 minutes.

Remember to whisk frequently so the white sauce doesn’t burn on the bottom. Lastly, whisk in miso, nutritional yeast, garlic, rosemary, and a bit of nutmeg if you have it.

Step 4: Assemble the Gratin.

Arrange peeled and sliced potatoes in a baking dish, and pour the sauce on top. Shake the pan a little to distribute the sauce all the way to the bottom layer of potatoes.

Step 5: Bake.

Cover with foil and bake until the potatoes are cooked through, about 1 hour. Lastly, uncover, sprinkle with the panko topping, and continue baking uncovered until the breadcrumbs are golden, about 15 minutes.

Make-Ahead Tips

These vegan scalloped potatoes are best eaten while still warm from the oven; they’re still delicious after that, but the topping gets a bit soggy. If you want to prep the gratin in advance, cook the sauce (through step 5 below) and refrigerate it for up to 3 days; peel and slice the potatoes, and store them in a container full of water in the fridge for up to 24 hours. Then assemble and bake day-of.

Alternatively, partially bake the assembled gratin (through step 6), cool it, and store covered in the fridge for up to 1 day; before serving, mix up the breadcrumb topping and finish baking.

More Dairy-Free Holiday Recipes…

• Celeriac Purée
• Stuffed Portobello Mushrooms
• Roasted Garlic Mashed Potatoes
• Cauliflower Pot Pie

Let me know if you try this recipe! Give it a rating below and leave a comment, and don’t forget to tag your creation with @thenewbaguette on Instagram.