Steps
1. Preheat oven to 350°F (175°C).
2. In a bowl, whisk together eggs, milk, salt, and pepper until well combined.
3. Stir in chopped spinach and feta cheese.
4. Lightly grease a small oven-safe muffin tin or ramekin with olive oil.
5. Pour the egg mixture into the muffin tin, filling about 3/4 full.
6. Bake for 15-18 minutes, or until eggs are set and slightly golden on top.
7. Remove from oven, let cool slightly, then gently loosen with a knife and serve warm.