01 - Preheat the oven to 400°F.
02 - Drizzle 1 tbsp olive oil in a medium ovenproof skillet or baking dish. Add the chopped spinach, cherry tomatoes, red onion, and garlic. Season with salt, black pepper, and oregano; toss to combine evenly.
03 - Crumble or place the feta cheese block over the vegetables. Drizzle with the remaining 1 tbsp olive oil.
04 - Bake for 10-12 minutes, until the tomatoes begin to soften and the feta starts to brown at the edges.
05 - Remove from the oven. Using a spoon, create four small wells in the vegetable mixture. Crack an egg into each well. Sprinkle with a pinch of salt, black pepper, and red pepper flakes if desired.
06 - Return to the oven and bake for another 8-10 minutes, or until the egg whites are just set but the yolks remain runny.
07 - Remove from the oven, garnish with fresh parsley or basil if desired, and serve immediately with toasted bread.