01 - Preheat oven to 350°F. Grease a 9-inch pie dish or baking dish lightly with oil or cooking spray.
02 - Heat a large skillet over medium heat. Sauté diced onion in a small amount of oil until translucent, approximately 3-4 minutes. Add chopped spinach and cook until wilted. Remove from heat.
03 - In a large mixing bowl, whisk together eggs, milk, cottage cheese, salt, pepper, and nutmeg until smooth and well combined. Stir in shredded cheese and fresh herbs if using.
04 - Add the cooked spinach and onion mixture to the egg mixture. Mix thoroughly to distribute vegetables evenly throughout.
05 - Pour the mixture into the prepared pie dish. Use a spatula to smooth the top surface evenly.
06 - Bake for 30-35 minutes until the center is set and the top is lightly golden brown. A knife inserted near the center should come out clean.
07 - Allow the quiche to cool for 5-10 minutes before slicing. This helps the custard set properly for cleaner cuts. Serve warm.