Leeks are related to onions and garlic, but have a more subtle flavour.
They have been cultivated by the ancient Egyptians and have been popular ever since.
They are best stored loosely wrapped in plastic to keep them from drying out and to keep their aroma contained.
The whole vegetable is edible, but make sure to scrub them thoroughly. You can remove the outer leaves if they are bruised.
They work in any dish that onions do.