A one-pan brunch dish that is packed with vegetables and loaded with the flavors of the Mediterranean. You can assemble the dish in advance and stow it in the refrigerator up to one day ahead of time, baking it just before serving. Feel free to cut the entire recipe in half and cook in a 9- or 10-inch saute pan, scaling the cooking time back to about 30 minutes.
Preheat oven to 350 degrees F.
Heat the olive oil in a large, deep pan, such as a 10 to 12-inch cast iron skillet, over medium heat. Add the onion and saute until nearly tender, 6 minutes. Add the frozen spinach and cook until defrosted and most of the liquid has evaporated. Remove from heat.
Add the artichoke hearts, sun-dried tomatoes, and bread and stir to mix all the ingredients with the spinach. Scatter the feta over the top.
In a medium bowl, whisk together the eggs, cottage cheese, oregano, salt, and several grinds of black pepper. Pour over the vegetables. Use your finger (or a small spoon) to gently nudge everything around in the pan so the egg is evenly distributed amongst the vegetable. Sprinkle the Pecorino Romano over the top. Bake immediately or cover and store in the fridge up to one day in advance (if you store in the fridge, take it out 30 minutes before baking).
Bake until the egg is just set with no obvious liquid remaining, 35 to 45 minutes depending on the size of the pan.
Cut into wedges and serve warm, at room temperature, or cold.