Frittata is a classic Spanish omelet that can be made ahead of time. And while the traditional frittata is made with onions and potatoes cooked in a generous amount of oil, you can use all sorts of vegetables to make a delicious version. Frittata is a great way to use up leftovers. Just chop whatever ingredient you have like roast chicken, or asparagus, or shrimp for variations on the theme.
