Set your oven to 400°F to begin heating.
If preparing individual portions, arrange tomatoes, bell pepper, onion, garlic, and feta evenly in four oven-safe ramekins and drizzle one tablespoon of olive oil over each.
For a single baking dish, mix tomatoes, bell pepper, onion, and garlic together and place the feta block in the center; pour olive oil over all.
Combine oregano, salt, thyme, black pepper, and red pepper flakes in a small bowl and sprinkle this spice blend over the veggies and cheese.
Place the ramekins on a baking tray or the large dish directly into the oven and roast for 25 minutes.
Once baked, remove from the oven and gently mix to blend the feta with the vegetables evenly, then stir in the chopped baby spinach.
Make a small well in the center of each ramekin or four wells if using one dish, then carefully crack an egg into each well.
Return the dishes to the oven and cook for another 10 minutes, until eggs are set to your liking.
Finish by topping with chopped fresh basil or chives if desired.
Serve warm, accompanied by crusty bread, toast, or pita for dipping.
