01 - Preheat oven to 350°F. Grease a 12-cup muffin tin or line with silicone muffin liners.
02 - In a large bowl, whisk together eggs and milk until evenly combined.
03 - Add spinach, green onions if using, feta, mozzarella or cheddar, salt, black pepper, garlic powder, and nutmeg. Stir until the mixture is well combined.
04 - Pour or ladle the egg mixture evenly into prepared muffin tin cups, filling each about two-thirds full.
05 - Bake for 18 to 20 minutes until the egg bites are firm and lightly golden on top.
06 - Allow to cool for 5 minutes in the tin. Run a knife around the edges, gently remove each egg bite, and serve warm or at room temperature.