Have you ever had cock-a-leekie soup? If so, you’ve tried leeks, simmered until sweet and tender with chicken. The long, thick alliums seem as if they’d be stronger than their onion cousins, but they melt into tender, sweet shreds upon cooking. Clean leeks well by slicing them lengthwise and washing out any trapped dirt. Then sauté thin slices in some oil or toss them in soups and you’ve got an all-purpose flavor boost. The light green and white parts are best; save the tougher dark greens for stock.