Preheat your oven to 375°F (190°C). Lightly grease a 9-inch pie dish or similar baking dish with olive oil or nonstick cooking spray.

Heat the olive oil in a skillet over medium heat. Add the chopped red onion and cook for 2–3 minutes until softened. Add the minced garlic and cook for another 30 seconds.

Add the chopped spinach and cook for 1–2 minutes, just until wilted. Remove from the heat and allow the mixture to cool slightly.

In a large mixing bowl, whisk together the eggs, milk, heavy cream, oregano, salt, black pepper, and red pepper flakes. Whisk until smooth and well combined.

Stir the cooled spinach mixture and chopped sun-dried tomatoes into the egg mixture. Add the crumbled feta and shredded mozzarella, reserving a small amount of feta for the top if desired.

Pour the mixture into the prepared baking dish and spread the ingredients evenly. Sprinkle the remaining feta and fresh parsley over the surface.

Bake uncovered for 35–40 minutes, or until the center is set and the top is lightly golden. The quiche should be firm around the edges with only a slight jiggle in the center.

Remove from the oven and let it rest for 5–10 minutes before slicing. This allows the eggs to finish setting and makes the quiche easier to serve.

Serving Suggestions

Serve warm with a fresh tomato and cucumber salad, roasted potatoes, avocado, or toasted whole-grain bread. It also makes an excellent brunch dish alongside fresh fruit.