Preheat your oven to 375°F (190°C). Grease a medium-sized 8-inch deep dish or oven-proof bowl lightly with olive oil.

In a skillet, heat the olive oil over medium heat. Add chopped onion and sauté until soft and translucent (about 3–4 minutes). Add minced garlic and stir for another 30 seconds until fragrant. Add the spinach and cook until wilted; season lightly with a pinch of salt and pepper. Remove from heat and let cool slightly.

In a mixing bowl, whisk the eggs, cottage cheese, heavy cream (or coconut milk), Dijon mustard (if using), salt, and black pepper until smooth and slightly frothy.

Fold in the sautéed spinach-onion mixture, crumbled feta, dried oregano, and red pepper flakes if using. Stir gently so that the spinach and feta distribute evenly.

Pour the mixture into the greased oven-proof bowl. Smooth the top with a spatula.

Bake in preheated oven for 28–32 minutes, or until the center is set — the surface should be lightly golden and the interior still slightly custardy. Avoid overbaking, or eggs may become rubbery.

Remove from oven and let it rest for 5 minutes. Garnish with fresh parsley or chives and a drizzle of olive oil (or add tomato slices) for a pop of freshness. Serve warm.