The heftier, milder cousin of onions and scallions, leeks can stand alone as a side dish, or punch up stews, cream soups, casseroles, and salads. Leeks come into their own between fall and spring, but these excellent keeping vegetables are key players in both summer and winter iconic soups, as well as autumnal braised fall dishes or springtime risottos, accompanied by peas and asparagus.
The first step to preparing leeks for cooking involves slicing off the inedible bits at either end. On the bottom, white end, slice off 1 inch or so -- the rounded section on which the little rootlets cling. The upper, green end contains several inches of dark green tough leaves; remove and discard them. To wash off as much dirt and debris as possible, slice the leek lengthwise almost to the bottom to open it up and hold it under cold running water. Alternatively, swirl it in one or two bowls of cold water.
A fall classic, braised leeks add heartiness to fish or chicken meals. After slicing two to four leeks lengthwise, turn them a one-quarter turn and slice lengthwise again. Braising them begins with sauteing the leeks in butter over medium heat, then adding enough broth, wine or water to cover them. After covering the pan, lower the heat and cook the leeks for another 5 minutes, until they are fork-tender. Herbs, lemons and spices added to the cooking liquid just before the braising process add additional flavor.
Like braising, sauteing leeks caramelizes their flavors, adding sweetness to pungency. Sauteed leek pieces may be served as a simple side dish but also work as an ingredient for risottos, quiches or root vegetable gratins. Sauteed leeks generally go into the pan in diced pieces. Chop leeks either before or after cleaning, then saute them in olive oil or butter, or a combination of the two fats. The leeks soften in about 15 minutes, at which point you can add seasonings, including garlic.
Used in very fine pieces, raw leeks add a bite to green salads. More commonly, however, cooked leeks make their appearance in vinegary salads, such as potato salad. After boiling potatoes and other additions such as green beans separately, toss them with cooked leeks that have been sliced crosswise into disks and sauteed. A dressing made of about 8-parts oil, 3-parts vinegar and 1-part Dijon mustard may be spooned over all the ingredients; top with chopped boiled eggs, chopped fresh herbs or crumbled bacon.
Sauteed leeks and potatoes are traditional partners in comforting but pungent creamy soup. After softening a few pounds of leeks along with a handful of vegetables, such as celery, onions and carrots in a sturdy stockpot, and adding a large potato, the veggies cook in 6 to 8 cups of a combination of wine, water and chicken stock. After thickening this aromatic mixture with a small amount of flour, use a blender to transform it into a thick, creamy soup. Swirl in a bit of heavy cream just before serving. A similar preparation exists for the elegant cold soup vichyssoise; to prepare it, simmer potatoes and leeks in water and puree them with milk and cream.