Preheat your oven to 400°F (200°C) and line a rimmed sheet pan with parchment paper to prevent sticking.
Place the diced bell peppers, zucchini, and red onion onto the pan and toss with olive oil, sea salt, black pepper, and garlic powder.
Roast the vegetables for 12-15 minutes until they are tender and just beginning to caramelize at the edges.
While the vegetables roast, whisk together the whole eggs, liquid egg whites, and nutritional yeast in a medium bowl until the mixture is well combined and slightly frothy.
Remove the sheet pan from the oven and spread the vegetables out evenly to create a base for the eggs.
Carefully pour the egg mixture over the vegetables, ensuring it stays within the boundaries of the parchment paper.
Sprinkle the crumbled feta cheese over the top and return the pan to the oven for 8-10 minutes, or until the eggs are completely set and fluffy.
Remove from the oven, garnish with freshly chopped parsley, and slice into squares for serving.