In a skillet sauté the mushrooms, onions, and spinach leaves until tender, remove from skillet.
In a small bowl stir together the remaining omelet ingredients except oil.
In the same skillet, heat oil. Pour egg mixture into skillet.
Cook over medium heat lifting slightly with spatula to allow uncooked portion to flow underneath until omelet is set (3-4 minutes).
Place sautéed mushrooms and spinach on half of omelet.
Gently fold other half of omelet over filling.
Serve hot.
Tip: For even fluffier omelets, add 1/3 cup of water, almond milk, or grassfed milk to the egg mixture before cooking.
Beat thoroughly.
