Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel and dice the sweet potato into half-inch cubes, then chop the bell peppers and zucchini into similar bite-sized pieces.
Place the sweet potato, peppers, zucchini, and cherry tomatoes on the baking sheet and drizzle with extra virgin olive oil.
Sprinkle with sea salt, black pepper, and dried oregano, then toss thoroughly to coat every piece of vegetable.
Roast the vegetables for 20 minutes, or until the sweet potatoes are tender and starting to lightly brown.
Remove the pan from the oven and use a spoon to create four large wells in the vegetable mixture.
Pour the liquid egg whites into the wells and carefully crack one whole egg into the center of each well.
Return the pan to the oven for 8 to 10 minutes until the whites are opaque and set, then top with crumbled feta, fresh parsley, and serve with Greek yogurt.