Au Gratin Yukons with Butternut Cashew Sauce

au gratin potatoes with cashew sauce in a white baking dish on a wooden table

With this creamy, rich sauce, you will not miss the dairy! The sauce can be used for any dish (think mac n’ cheese, pastas, and more) that usually calls for a dairy-based cream sauce.

Serves: 10

  • 1 whole butternut squash*
  • 2 teaspoons olive oil
  • 1 teaspoon turmeric
  • 1/2 teaspoon chili flakes
  • 1 small onion, diced
  • 1-3/4 ounces raw cashews
  • 2 tablespoons white wine
  • 2/3 cup nutritional yeast
  • 1 teaspoon fresh garlic
  • 1-1/4 tablespoons apple cider vinegar
  • 1-1/4 cups water
  • 1 teaspoon kosher salt
  • 1 pound Yukon potatoes, sliced thin

Preheat oven to 400 degrees F. Dry roast the butternut squash by cooking it whole on a sheet pan with the skin on for an hour until squash is soft and brown. After the squash is roasted, let cool on the baking sheet, then remove skin by peeling with a large knife or vegetable peeler and cut down the middle and scoop out the seeds. Cut squash into 1-inch cubes, reserving 2 cups for the sauce.

When squash is ready, heat oil in a medium pan. Add turmeric and chili flakes and cook until they become fragrant, about 1-2 minutes. Add the diced onion, cooked butternut squash, and cashews. Sauté until caramelized, about 10-12 minutes.

Deglaze the pan with white wine and continue cooking until the liquid is reduced by half, about 5 minutes more. Add the nutritional yeast, garlic, vinegar, salt, and water. Remove the pan from heat and add the ingredients to a blender or food processor. Being cautious not to splatter the hot mixture, blend the sauce for 5-8 minutes until it appears smooth and a bit shiny.

Arrange a layer of sliced potatoes into a 9×13 inch or 2-quart baking dish lightly coated with cooking spray. Top with 1/3 of the blended sauce. Continue adding layers of potato and sauce, ending with a final layer of sauce. Bake at 350 degrees F until tender and browned, about 30-40 minutes. Garnish with parsley or dill.

*If you have the equipment, smoking is also a terrific way to cook the squash and will add another layer of flavor.