Few vegetables can stand sentry against winter's rigors, safeguarding the ideal of eating with the seasons.

Few vegetables can stand sentry against winter's rigors, safeguarding the ideal of eating with the seasons.

Come February, the squashes, potatoes and garlic harvested in fall either have been consumed or are starting to shake off attempts at storage. One member of the allium family, however, can remain snug in the soil for farmers and gardeners who had the foresight to sow it the previous spring or early summer.

Leeks, like garlic, are the very definition of a long-season crop, requiring a good six months to size up for harvest. But leeks' almost unmatched hardiness permits growth, albeit slow, through cold weather with only a little frostbite on their tough, uppermost leaves, usually discarded before cooking, anyway. Whole leeks keep, refrigerated, for about a month.

And like hardy greens, leeks sweeten with some frost exposure, making February and March — before leeks start to go to seed — the prime time to incorporate them in all manner of dishes. Gentle roasting caramelizes leeks and maximizes their sweetness, cooking in liquid renders them meltingly tender and a quick stint in hot oil delicately crisps strips of leek.

Leeks' subtle, onionlike, almost buttery flavor is finding more favor in American kitchens after centuries of use primarily by European cooks. France couldn't have its vichyssoise, a cold, potato-based soup, or Scotland its chicken soup, known as "cockaleekie," without leeks.

The culinary history of leeks dates to ancient Egypt, where drawings of the vegetable adorned pyramid tombs. The ancient Romans also valued leeks, considering them superior to onions and garlic, which were regarded as food for the masses.

Legend has it that 7th-century Welsh warriors wore leeks in their caps to distinguish them from the enemy in their victorious struggle against the Saxons. Thereafter, the leek became the symbol of Wales.

For modern cooks, leeks usually symbolize one of the dirtier vegetables. The numerous, tightly packed layers that make up a leek often are repositories of sand and grit. Depending on the method of preparation, leeks either can be halved lengthwise and doused with cold, running water; sliced crosswise and rinsed in a colander; or submerged underwater to dissolve dirt.

Before rinsing leeks, trim away the roots and green, upper leaves at the point where the color begins to pale. Wash the fibrous fan of dark-green leaves and save it to use in stock.

Soups and stews are obvious repositories of leeks. But dishes from pasta and stir-fry to quiche and casserole can accommodate them. Leeks also can be sauteed, braised or grilled on their own for a side dish.

To cook whole leeks, arrange them in one layer in the bottom of a large saucepan and pour in boiling water or stock until they're half covered. Season leeks with salt and pepper, partially cover and simmer until tender, about 12 minutes or more, depending on their size and age. For a richer flavor, saute leeks in butter before adding cooking liquid.

For grilling, halve leeks lengthwise, brush with oil and grill, cut-sides down, over medium-high heat or medium-hot coals for 7 to 10 minutes. Turn and continue grilling for 5 to 7 minutes or until tender. Smaller leeks can be skewered for ease of cooking over gas or charcoal grills.

The recipes on the next page use several techniques — steaming, roasting and frying — to lengthen leeks' wintertime welcome.