Preheat your oven to 375°F (190°C).
Finely chop the broccoli florets into bite-sized pieces and mince the garlic and red onion.
In a medium mixing bowl, whisk together the whole eggs, liquid egg whites, sea salt, and black pepper until the mixture is uniform and slightly frothy.
Heat the extra virgin olive oil in a 10-inch oven-safe non-stick skillet over medium heat.
Add the red onion and broccoli florets to the skillet and sauté for 4-5 minutes until the broccoli is tender-crisp and the onions are translucent.
Stir in the minced garlic and green peas, cooking for just 1 minute until the garlic is fragrant.
Pour the egg mixture over the vegetables in the skillet, tilting the pan to ensure the eggs cover everything evenly.
Sprinkle the crumbled feta cheese across the top of the egg mixture.
Allow the frittata to cook undisturbed on the stovetop for 2-3 minutes until the edges are set.
Transfer the skillet to the preheated oven and bake for 10-12 minutes, or until the center is firm to the touch and the top is lightly golden.
Remove from the oven and let it rest for 2 minutes before slicing into wedges and serving.