Preheat oven to 350 degrees F.

In preheated skillet, add olive oil, garlic, salt, and pepper. Sauté, stirring frequently, until just lightly golden brown. 

Add cornstarch and whisk to incorporate. Cook for 1 minute. 

Add almond milk a little at a time, whisking to incorporate. Whisk slowly to prevent clumps. 

Continue until all the almond milk has been added. Then add vegetable broth. Whisk to incorporate. 

Reduce heat to low. Let simmer to thicken, whisking frequently. Do not let burn on bottom. 

Turn off heat. Transfer sauce to blender and add nutmeg, and nutritional yeast. 

Blend on high until creamy and smooth. Taste and adjust seasonings as needed, adding more nutmeg, salt, pepper, or nutritional yeast to taste. Mixture should be very cheesy and a bit salty (this seasons the potatoes) 

Generously grease with oil or vegan butter, hotel pans or baking pans all the way up the sides.  

Layer half the sliced potatoes on bottom of pan and season with salt and pepper. Toss to coat.  

Cover with half of the onions and chorizo, spreading evenly. Lay flat and sprinkle on half the vegan parmesan. 

Add remaining potatoes, season with a bit more salt and pepper, and loosely toss. 

Pour sauce over the potatoes and add remaining vegan parmesan cheese, chorizo, and onions. Push down with your fingers to submerge everything. 

The sauce should just cover the potatoes. Remove any potatoes that are above the surface. 

Cover with foil and bake on middle rack of oven for 20 minutes. Then remove foil and bake for another 40-45 minutes (a total of 1 hour – 1 hour 5 minutes).  

Potatoes are done when knife inserted into the potatoes comes out without effort and the top is golden brown and bubbly. 

Remove from oven and let cool for 15 minutes before serving.  

As an optional garnish, top with fresh parsley and a dash of paprika for extra color.