Preheat your oven to 375°F (190°C).
Lightly grease a small oven-safe baking dish with the extra virgin olive oil.
Add the cherry tomatoes to the dish and roast for 10 minutes until the skins begin to blister and soften.
In a medium mixing bowl, whisk together the whole eggs, liquid egg whites, sea salt, black pepper, and dried oregano until well combined.
Remove the baking dish from the oven and stir in the baby spinach, allowing the residual heat to slightly wilt the leaves.
Pour the egg mixture over the roasted tomatoes and spinach in the baking dish.
Sprinkle the crumbled feta cheese evenly over the top of the egg mixture.
Place the dish back in the oven and bake for 15-20 minutes, or until the eggs are fully set and the top is lightly golden.
Let the dish rest for 2 minutes before slicing and serving warm.