As seen on: Giada’s Holiday Handbook, Episode 4. Santa’s Grab Bag.
Whisk eggs and milk in a medium mixing bowl.
Melt butter in large skillet over medium-low heat. Add spinach to skillet, stirring until reduced. Pour egg mixture into skillet over spinach. Cook slowly, stirring so that omelet cooks evenly. Add feta cheese along center the omelet. Using a spatula loosen sides of omelet from pan and fold one side over the other forming a half moon. Allow omelet to cook slowly while cheese melts. Approximately 2 minutes. Slide omelet onto plate. Season with pepper and salt to taste.