Preheat your oven to 400°F (200°C). Lightly oil four individual 6-ounce white ceramic baking dishes or a single 9x9 inch baking dish. Prepare all ingredients: cube the feta, halve the tomatoes, mince the garlic, and slice the green onions, keeping the white and green parts separate.

In a large skillet over medium heat, warm 2 tablespoons of olive oil. Add the white parts of the green onions and the minced garlic. Sauté for 1-2 minutes until fragrant. Add the spinach and cook, stirring, for another 1-2 minutes until just wilted. Remove from heat.

Divide the sautéed spinach mixture evenly among the prepared baking dishes. Scatter the cubed feta and halved cherry tomatoes over the spinach. Sprinkle with dried oregano, red pepper flakes (if using), and black pepper. Drizzle lightly with a little more olive oil.

Place the dishes on a baking sheet (for easy handling) and bake in the preheated oven for 15-18 minutes. The feta should be soft and starting to get golden spots, and the tomatoes will begin to blister and release their juices.

Carefully remove the baking sheet from the oven. Use a spoon to create a small well in the center of each dish. Crack one egg into each well. Return to the oven and bake for 8-12 minutes more, or until the egg whites are set and the yolks reach your desired consistency.

Remove from the oven. Immediately garnish with the green parts of the sliced onions and fresh herbs. Let cool for 2-3 minutes before serving directly in the hot baking dishes, accompanied by toasted bread for dipping.