Finely dice the red bell pepper and roughly chop the fresh spinach.
In a medium bowl, whisk together the whole eggs, liquid egg whites, Greek yogurt, sea salt, black pepper, and garlic powder until the yogurt is well incorporated and the mixture is smooth.
Heat the olive oil in a non-stick skillet over medium heat.
Add the diced red bell pepper to the skillet and sauté for 3 to 4 minutes until softened.
Add the spinach to the pan and cook for 1 minute until just wilted.
Lower the heat to medium-low and pour the egg mixture into the skillet.
Using a spatula, gently stir the eggs, pushing them from the edges toward the center to create soft, creamy curds.
Just before the eggs are fully set, sprinkle the crumbled feta cheese over the top.
Remove from heat while the eggs still look slightly moist, as they will continue to cook for a moment on the plate.
Serve immediately while hot and creamy.