Preheat your oven to 191 °C (190 °C).

Heat 15 ml of olive oil in a 10-inch ovenproof skillet over medium heat. Add the diced onion and sauté for 4 to 5 minutes until soft and translucent, then add the minced garlic, dried oregano, red pepper flakes, salt, and black pepper, cooking for another 1 minute until fragrant.

Add the chopped fresh spinach in batches, stirring constantly until wilted. Stir in the drained white beans, tossing everything together to combine thoroughly and warm through.

Use the back of a large spoon to create 4 shallow wells in the spinach and bean mixture. Crack one egg directly into each well. Scatter the crumbled feta cheese evenly over the top and drizzle with the remaining 15 ml of olive oil.

Transfer the skillet to the preheated oven and bake for 10 to 14 minutes, or until the egg whites are fully set but the yolks remain soft and runny.

Carefully remove the hot skillet using oven mitts. Garnish with chopped fresh dill or parsley and serve warm directly from the pan.