Preheat your oven to 400°F (200°C).
In a small oven-safe skillet or ceramic baking dish, toss the cherry tomatoes with extra virgin olive oil, sea salt, black pepper, and dried oregano.
Roast the tomatoes in the oven for 10 to 12 minutes until they are blistered and have started to release their juices.
Remove the skillet from the oven and stir in the fresh spinach until it is just slightly wilted from the heat.
Carefully pour the liquid egg whites over the vegetable mixture, then crack the two whole eggs directly on top, spaced evenly apart.
Sprinkle the crumbled feta cheese over the top of the egg mixture.
Place the skillet back into the oven and bake for 8 to 10 minutes, or until the whites are fully set but the yolks remain soft and runny.
While the eggs bake, toast the sourdough bread until golden and crisp.
Remove the skillet from the oven and serve immediately with the toasted sourdough for dipping into the warm yolks.