Preheat your oven to 400 degrees Fahrenheit.

To prepare the sauce, add the soaked and drained cashews, water, nutritional yeast, salt, pepper, and garlic to a small blender. Blend until completely smooth. Set aside.

To prepare the parmesan cheese, add the mixed nuts, nutritional yeast, and salt to a dry blender. Blend until you have a fine, parmesan-like consistency. Set aside.

Grease a 9x13 baking dish with coconut oil.

Add a layer of the sliced potatoes, sliced onions, a pinch of salt and pepper, and 1/4 of the prepared sauce. Repeat the layering process two more times. On your forth layer, add only the potatoes, salt, and pepper, and sauce. Sprinkle the prepared parmesan cheese on top.

Bake in your preheated oven covered for 30 minutes. After 30 minutes, bake for an additional 30-35 minutes uncovered, or until potatoes are tender and golden brown.

Let sit for a few minutes before serving. Garnish with fresh chives, if desired.