This Spinach-Feta Egg-White Onelet is a light version of a Greek diner classic. // Here's a tip on how to make this the best possible way: Cook the omelet at a low temperature. This will prevent it from browning and will create a fine texture. Make sure to use a rubber spatula when cooking the omelet. Metal spatulas will break the egg whites and make it impossible to transfer the omelet in one piece. If you are adding toppings to the omelet, warm them first if you’re planning to add them at the end. They won't be heated through in the time it takes to cook the omelet.