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Cauliflower and Potato Gratin


Cauliflower and potato gratin

This recipe was shared with us courtesy of Chef Simone Bonelli of soon to be opened Nossa Restaurant in Los Angeles. This cheesy, hearty recipe works amazingly well with our Unsweetened Original Oat Milk. Although you may have thought oat milk is best for coffee or tea, this dish proves it’s a must-have for home chefs as well. 

The foundation of this recipe is the baked potato and cauliflower. For the potatoes, we recommend Kennet potatoes, but yukon golds will work as well. Be sure to blanch the potatoes and cauliflower to get them tender and moist before baking.

And of course you wouldn't have a gratin without cheese. We used parmigiano reggiano and fontina. This can be made dairy-free by substituting them with a vegan parmesan cheese or omitting the cheese altogether.


  • 1.5 lb potato, sliced about ¼ inch thick on a mandolin
  • 1.5 lb cauliflower (about a half of a large head), cut into florets
  • 1 large white onion, sliced about ½ inch thick
  • 2 garlic cloves, thinly sliced
  • ¼ cup Sage, roughly chopped
  • ¼ cup rosemary, roughly chopped
  • 3 tablespoons flour
  • 2 cups Willa’s Unsweetened Original Oat Milk
  • 1 tablespoon olive oil + 1 ½ tablespoons olive oil
  • 1 teaspoon salt + ⅛ teaspoon salt
  • ⅛ teaspoon nutmeg
  • 1 egg + 1 egg yolk
  • ¼ cup grated parmigiano reggiano cheese
  • ¼ cup grated fontina cheese (or any other soft cow’s cheese will suffice!)


  1. Preheat the oven to 375. 
  2. In a medium pan, sweat onion and garlic over medium heat in olive oil until onions are translucent, about 20 minutes.  Set aside.

Blanching the cauliflower and potatoes

  1. In a medium pot, boil about 4 quarts of water with 1 tsp salt.  Once the water is boiling, add cauliflower florets and boil for 1 minute.  Remove from water (reserving water for potatoes).  Set blanched cauliflower aside. 
  2. Bring water back to a boil and blanch potatoes for 2 minutes.  Remove from water and set aside. 

Preparing your Willa’s Unsweetened Original Oat Milk Bechamel: 

  1. Whisk together 3 tablespoons flour and 1½  tablespoons olive oil in a medium saucepan.  Once combined, gently whisk in the 2 cups of Willa’s Unsweetened Original Oat Milk, a little at a time.  Add ⅛ teaspoon of salt and ⅛ teaspoon nutmeg.  Gently warm over medium heat and whisk often.   Continue to whisk until the bechamel boils.   Once the sauce boils, remove from heat.  It should be thick enough to coat the back of a spoon.  Allow to cool for about 5 minutes, then slowly whisk in the egg and the egg yolk. 
  2. Assemble your gratin.   When layering the ingredients, keep in mind that you will create 2 layers. Frist, lightly coat the bottom of a 9x13 baking dish with bechamel. Then, top with a sparse layer of the onions. Arrange the potatoes so that one full layer completely covers the dish like shingles (After each potato layer, press gently to make sure the layer is even to compress the ingredients slightly).Top with a sparse layer of the cauliflower, then a dusting of the chopped rosemary and sage, then a sparse layer of the grated fontina, then a sparse layer of the grated parmigiano.
  3. Repeat layers, starting with bechamel. Once your last last layer is complete with the parmigiano, top with the remaining herbs and fresh black pepper. 
  4. Wipe the edges of the dish and bake for 45 minutes, until the top is golden brown and lightly crispy.
  5. Let cool and enjoy!  Great served as a side dish, or top with a fried egg for post holiday brunch!

Looking to do more baking with oat milk? Try our Easy Dairy-Free Bread, Almond and Oat Pumpkin Bread, or our Fall Breakfast Muffins recipe.

For desserts that use Willa’s Oat Milk, try our Oat Milk Pumpkin Pie, Oat Milk Chocolate Pudding, or Dairy-Free Vanilla Cupcake recipe.

All of our recipes, including coffee and cocktails, can be found here.

To learn more about the health benefits of whole grain oat milk, sustainability, and more, check out our blog.