Once the fathead crust is in the oven, add the asparagus spears to another baking sheet. Top the asparagus with 1 tablespoon avocado oil and salt and pepper to taste. Place in the oven with the fathead crust for 10 minutes.
Next move onto the onions. Add the remaining 1 tablespoon avocado oil to a skillet over medium heat. Saute the onions for 10-15 minutes or until lightly browned and softened.
For the Hollandaise Sauce
While the flatbread, asparagus and onions are cooking, start on the Hollandaise sauce.
Fill a saucepan with about 1 inch of water. Bring it to a simmer over medium-low heat on the stove stop.
Whisk your egg yolks and lemon juice together in a heat-proof bowl (like stainless steel) until thickened.
Place the bowl on top of the saucepan - make sure the water doesn't touch the bottom of the bowl!
Whisk the yolk mixture rapidly, then slowly drizzle in the melted butter and sprinkle with salt. Whisk until the mixture as doubled in size and is nice and thick! Keep the sauce warm until ready to use.