Preheat the oven to 400°F (200°C).
Divide the tomatoes, bell pepper, red onion, garlic, and feta evenly into 4 oven-safe ramekins, or combine in a single large baking dish with the feta block in the center.
Drizzle olive oil evenly over the veggies and feta—1 tablespoon per ramekin or all 4 tablespoons over the large dish.
Mix oregano, salt, thyme, pepper, and red pepper flakes in a small bowl, then sprinkle the seasoning evenly over the veggies and cheese.
Place ramekins on a baking sheet for stability if using, then bake for 25 minutes until tomatoes are roasted and feta is soft and golden.
Remove from oven, gently stir to break up the feta and blend the vegetables, then fold in chopped spinach.
Create small wells in the mixture—one per ramekin or four in the large dish—and crack one egg into each well.
Return to the oven and bake for 8 to 10 minutes until egg whites are set but yolks remain soft, or longer for firmer yolks.
Garnish with fresh herbs if desired and serve warm or at room temperature with crusty bread or pita.