Preheat your oven to 400°F and line a rimmed sheet pan with parchment paper for easy cleanup.
Dice the red bell pepper, zucchini, and red onion into small, uniform pieces to ensure even cooking.
Place the vegetables on the prepared sheet pan and toss with avocado oil, sea salt, black pepper, and garlic powder.
Roast the vegetables for 10-12 minutes until they are tender and just beginning to show caramelized edges.
While the vegetables roast, whisk together the whole eggs and egg whites in a large bowl until the mixture is completely smooth.
Remove the pan from the oven, spread the roasted vegetables evenly across the surface, and carefully pour the egg mixture over them.
Sprinkle the crumbled feta cheese evenly over the top of the eggs.
Return the pan to the oven and bake for 10-12 minutes or until the eggs are fully set and slightly golden on top.
Garnish with fresh chopped parsley and slice into squares before serving hot.