Now that St. Patrick’s Day has safely passed, I can talk about leeks. (This only makes sense if you read my column last week.)

Leeks are a member of the Lily family, Allium, a large family that includes all onions and garlic. Leeks, as we know them today, were cultivated thousands of years ago from wild leaks (Similar to the wild leeks we called “ramps” found growing in the woodlands in Ontario when I was at camp; used to season our hunter’s stews.) and wild garlic (ramsons) that grew in damp woodlands all across Asia, Europe, and the British Isles. The wild plants were smaller and far more pungent, with a stronger onion/garlic flavour than the leeks we know today.

It was likely the Egyptians who first cultivated the modern version of leeks. The conquering Romans took a strong liking to the new leeks, and took the “new” vegetable with them across Europe and into the British Isles.

The cultivated leek, because it grew so well in the climate of the British Isles, quickly became an important part of their diet, as well as their folklore. In Scotland, cock-a-leekie soup became a national dish: take one cock, some leeks, possibly prunes, and simmer. In Wales, the leek became important for more than just diet. In the war against the Saxons in 640 AD, it is said that the Welsh wore a leek on their cap to prevent their soldiers from shooting each other. Now, if you take a look at a typical leek in the produce section, you quickly realize that this is pretty far fetched. It is more likely that they wore wild garlic. The Saxon word leac means any onion or garlic. None-the-less, the leek became their national symbol.

France, where the leak is known as the “King of soup onions” and by the less-lordly title, “Poor-man’s asparagus,” is today the largest consumer and producer of leeks. From their famous cold potato and leek soup, Vichyssoise, to quiche and gratins, the French love their leeks.

Why is the leek so revered in other countries? It is possible that our misunderstanding of basic leek physiology is the problem. Over-cooked and under-washed leeks will net you gritty slime. Raw leeks are like raw potatoes: starchy and unpleasant.

Cultivated leeks are grown in a hill of soil that is increasingly piled up around the stalk in order to keep it white: you know, photosynthesis and all that high school biology stuff. This process also ensures that one of the more annoying characteristics of leeks is maintained: they are notorious dirt-collectors. You will find in any recipe book exhaustive directions for properly cleaning leeks. The first step in preparing any leek is to remove the tough dark-green leaves. These should be saved for making vegetable broth. Don’t rashly chop off the whole top either; there are tender, edible pale-green leaves hidden inside. If you are going to be chopping or slicing the leeks, the cleaning process is fairly simple, only requiring soaking in several changes of water followed by several rinses in a colander. If you decide that you want to be more adventuresome and use the whole stem for a dish, you are up against a more formidable opponent.

After the stalk is trimmed, soak and drain the whole stalks, then carefully make two slits lengthwise down the stock and, holding these under the tap, allow water to run inside and drain out, repeatedly.

Another way to grow leeks is to place a collar around the emerging stalk to keep the sun away. This apparently also keeps the leeks from collecting so much sand. I suppose you could just look for leeks grown this way.

Leeks must be cooked before eating. Even baby leeks, which aren’t easy to come by, need a brief immersion in hot water. Even if you intend to use them cold in a salad or in any other baked dish, they need to be blanched first. This need only be a minute of steaming or boiling for more tender leeks, up to several minutes for older, thicker stalks. This can also be done in a microwave by first chopping the stem and nuking with a bit of water.

The easiest way to cook leeks is by braising them in a seasoned broth or by lightly sautéing. However, leeks must never be over-cooked. They contain a component that is like mucilage, and if cooked too long, become slimy.

If you look in any cookbook, especially low-fat or vegetarian ones, you will find soup recipes that use purée of leeks as the base. The property that makes leeks gluey when overcooked makes them a perfect non-fat thickener. Leeks that have been cooked either with potatoes or without, and then puréed with either cream, low-fat milk, or simply a vegetarian broth, make a beautiful creamy soup or sauce. You can go from the rich, cream laden French Vichyssoise to an ultra-low-fat diet food with leeks.

This no-fat soup is part of a diet found in the book—which I swear I never read— called “French Women Don’t Get Fat,” by Mireille Guiliano, a bird-like size one woman I saw on Oprah once. Among some otherwise sensible suggestions, she makes a soup she eats on weekends when she is feeling particularly fat—perhaps she has to wear her size two pants? The soup is leeks cooked in water; apparently quite satisfying and filling. She calls it her “Magical Leek Soup.”

Leeks aren’t just for soup. Once you understand the vegetable better, you will find all sorts of uses for them. They can be kept whole and baked with cheese or layered in tortes and vegetable strudels. They can be added to frittatas and quiches, served cold with a vinaigrette dressing, or grilled on the barbecue.

We are really nearing the end of good leek season, which is generally considered to be from fall to early spring, although now that leeks are grown commercially in places such as Florida and California, we can expect this “season” to be stretched. Watch for bulbous bases; a sign that the leeks are old and have a woody core.

Perhaps for next St. Pat’s Day, I will make a batch of Colcannon, the traditional Irish side-dish made from potatoes, cabbage, and leeks.