Heat oil in a medium skillet over medium low heat. Add onions and cook, stirring frequently, until translucent, about 5 minutes. Sprinkle with salt and continue to cook, stirring frequently, until onions are golden and soft, about 15 more minutes.
White Pizza Sauce:
In a medium bowl, whisk together the mayo, cashew milk, and nutritional yeast until smooth. Set aside.
Preheat oven to 350F.
In a large bowl, whisk together the almond flour, coconut flour, baking powder, garlic powder, pizza seasoning, and salt. Stir in egg whites, avocado oil, and cashew milk until dough comes together (it will still be quite sticky).
Spray a large piece of parchment with coconut oil spray or brush with oil. Turn half of the dough out onto the parchment and pat into a disk. Cover with another piece of parchment or waxed paper and roll out to a circle about 10 inches in diameter. Repeat with remaining dough.
Set parchment paper with dough onto a pizza stone or large baking sheet. Bake 20 minutes, or until firm to the touch and golden brown around the edges.
Remove from oven and spread with white pizza sauce, then sprinkle with caramelized onions. Bake 7 minutes, until toppings are warmed through.
Remove and sprinkle with freshly ground pepper and chopped fresh basil, if desired.
Serves 8. Each serving has 12.44 g of carbs and 5.88 g of fiber. Total NET CARBS = 6.56 g.Food energy: 322kcal Total fat: 30.93g Calories from fat: 278 Cholesterol: -- Carbohydrate: 12.44g Total dietary fiber: 5.88g Protein: 9.21g