Althea Brown’s Whole30 Sweet Potato Gratin

Althea Brown’s Whole30 Sweet Potato Gratin

This gratin is one of recipe developer Althea Brown’s favorite make-ahead side dishes and a Whole30 community favorite. Thinly sliced sweet potato coins are layered and microwaved with a vegan, gluten-free “béchamel” sauce made with coconut and cashew milk, cassava flour, and seasonings. Use orange or white sweet potatoes (or both) to create a stunning spiral pattern that tastes as good as it looks.

All of Anyday’s recipes are tested (and retested!) in many different microwaves and home kitchens to make sure they work — and work well.


Select your microwave wattage in the dropdown. The cook times in this recipe will automatically change accordingly.

To find your microwave’s wattage, look at the front panel, the side of the door, in the back, in the user manual, or Google the model number. If both an input and output wattage are listed, use the output.

Wattage translates to how powerful the microwave is. The higher the wattage, the faster your food will cook. The lower the wattage, the longer the cook time.

When in doubt, start with less time — you can always add more.


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Product Size

  • Small Dish
  • Medium Shallow
  • Large Shallow
  • Medium Deep
  • Large Deep

Prep Time

10 mins

Cook Time

9-11 mins

Free Time

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  • 1 tablespoon coconut oil
  • ½ cup (120ml) full fat coconut milk
  • ½ cup (120ml) almond or cashew milk
  • 1 tablespoon cassava flour
  • ½ tablespoon onion powder
  • ½ teaspoon garlic powder
  • salt, to taste
  • black pepper, to taste
  • ½ teaspoon nutmeg
  • 1 tablespoon nutritional yeast
  • 2 tablespoons parsley, finely chopped
  • 1 ½ (180g) sweet potatoes or yams, peeled and thinly sliced
  • smoked paprika, for garnish


  1. Place the coconut oil, coconut milk, cashew milk, cassava flour, onion powder, garlic powder, salt, black pepper, and nutmeg into the Anyday dish and whisk until fully incorporated. Cover with the lid (knob lifted). 
  2. Cook in the microwave for 1-2 minutes, then whisk. Add the nutritional yeast and parsley and mix to combine. Put mixture in a separate bowl and set aside. 
  3. Add ¼ cup of sauce to the bottom of the Anyday dish. Next, add a layer of sweet potato slices, then top with another ¼ cup of sauce. Continue to layer until all your sauce and potatoes have been used. Finish it off with a sprinkle of smoked paprika on top.
  4. Cover and continue cooking for 9 minutes, or until the sweet potatoes are tender when pierced with a fork. Keep in mind that the cooking will vary depending on the thickness of the sweet potatoes.

Serving suggestions & tips

  • If cashew or almond aren’t available, use any plant-based milk of your liking.
  • Microwave ovens vary, even with the same wattages. Adjust cooking times as needed.