Trim the white ends off of the asparagus.

In a large cast-iron pan, over medium heat, warm the cooking oil. Once hot, add in the asparagus and white onion.

Sauté until the onions start to clear, then add in the mushrooms. Adjust heat to medium-low and sauté until the mushrooms soften and reduce in size, stirring occasionally.

Place the sautéed mixture in a bowl and set aside.

Place the veggie broth, chickpea flour, nutritional yeast, Vegg powder, salt and pepper into a blender and puree until completely smooth.

Warm the same large cast-iron pan over medium heat, and coat with a thin layer of oil.

Pour the omelette batter into the hot pan and cook for 3 minutes before filling half of the omelette with the sautéed veggie mix.

Cook for an additional 2-4 minutes, until the edges brown and lift slightly, making sure to pop any large bubbles.

Carefully separate the edge of the omelette from the pan and use a large spatula to flip the empty half on top of the veggies. Adjust heat to very low, just to keep warm while preparing the sauce.

Whisk all ingredients together in a small, unheated pot until the cornstarch dissolves. Bring to a boil, stirring frequently, and lower to a simmer. Stir over heat until the sauce thickens and take off of heat.

Pour the sauce over the omelette and serve hot, preferably with a mimosa.