Preheat your oven to 375°F (190°C) and line a small rimmed sheet pan with parchment paper for easy cleanup.
Finely chop the broccoli florets, dice the bell pepper, and mince the red onion into uniform pieces.
Place the vegetables on the sheet pan, drizzle with olive oil, and season with half of the salt, pepper, and garlic powder.
Toss the vegetables to coat evenly and roast in the oven for 10 to 12 minutes until they are slightly tender and fragrant.
In a medium bowl, whisk together the whole eggs, liquid egg whites, and the remaining seasonings until the mixture is well combined and frothy.
Remove the sheet pan from the oven and carefully pour the egg mixture over the roasted vegetables, ensuring they are evenly distributed.
Return the pan to the oven and bake for an additional 10 to 15 minutes, or until the eggs are set in the center and slightly golden on the edges.
Sprinkle the crumbled feta cheese over the hot eggs and allow it to soften for a minute before slicing into squares and serving warm.