Clean and slice the cremini mushrooms and finely mince the fresh chives.
In a medium-sized bowl, whisk together the large eggs, liquid egg whites, sea salt, and black pepper until the mixture is uniform.
Place a large non-stick skillet over medium heat and add the avocado oil.
Add the sliced mushrooms to the skillet and sauté for 4 to 5 minutes until they release their moisture and turn golden brown.
Add the baby spinach to the pan and stir for about 1 minute until the leaves are just wilted.
Lower the heat to medium-low and pour the egg mixture over the vegetables.
Using a silicone spatula, gently push the eggs from the edges toward the center, creating large, soft curds until the eggs are just set.
Remove the skillet from the heat and fold in the crumbled feta cheese and fresh chives.
Toast the sprouted grain bread until crisp and serve immediately alongside the hot scramble.