01 - Preheat oven to 350°F. Grease a 9-inch pie dish or baking dish with cooking spray or a small amount of oil.
02 - Heat a large skillet over medium heat with a small amount of oil. Sauté diced onion for 3-4 minutes until translucent. Add fresh spinach and cook until wilted, about 2-3 minutes. Remove from heat and set aside.
03 - In a large mixing bowl, whisk together eggs, milk, cottage cheese, salt, pepper, and nutmeg until well combined. Stir in shredded cheese and fresh herbs if using.
04 - Add the cooked spinach and onion mixture to the egg mixture. Stir thoroughly to distribute vegetables evenly throughout.
05 - Pour the mixture into the prepared pie dish. Use a spatula to smooth the top evenly. Bake for 30-35 minutes until the center is set and the top is lightly golden. A knife inserted in the center should come out clean.
06 - Remove from oven and allow the quiche to cool for 5-10 minutes before slicing. This resting period helps the quiche set and makes cutting easier.