Prepare the vegetables using your Veggie Bullet. With the Slicer Blade, slice the sweet potatoes. Then, spiralize the Spanish onions.
Toast the minced garlic in a shallow stainless steel pot. Once toasty, add in ½ of the spiralized onions. Cook until translucent.
Deglaze the pot with the cooking wine and reduce by two-thirds.
Add in cream and bring to a simmer. Add in ½ a micro-planed nutmeg.
Season to taste with salt and pepper.
In a greased loaf pan, spoon some of the creamy mixture onto the bottom. Put in a layer of sweet potatoes and add on a layer of Gruyere cheese.
Repeat until the ingredients are gone. Make sure the last layer is cheese and top with the Parmesan. Press down to compress.
Bake for 30 to 40 minutes. The middle will be soft and the top should be nice and caramelized.
While cooking, heat up some canola oil in a large heavy duty pan. It should be enough oil to fully submerge the rest of the spiralized onions. Once the oil is at 300 degrees, turn the heat to medium and add the onions. Be careful! The pot must be big enough to absorb the water expansion in the onions. Use a big enough pot.
Mix them around with a fork until golden brown. Fish them out with a mesh strainer and put onto towels to dry. Fluff them up with two forks. Season with salt while warm. Use your crispy onions to garnish your gratin.