Don't let the delicate demeanor of watercress fool you. It's a potently flavorful plant and a nutritional powerhouse.
Along with radish and wasabi, watercress is a member of the mustard family, and it delivers a suitably peppery bite. It typically grows in or near water, so it's often hydroponically cultivated. Watercress has hollow stems and small white and green flower clusters.
A native perennial in Europe and Asia, watercress now grows in many regions of the world, especially the UK. In the United States, Huntsville, Alabama, calls itself the watercress capital of the world.
Serving for serving, watercress contains more iron than spinach, more calcium than milk and three times the vitamin E as lettuce. It's also a very good source of vitamins A, C, K, B6, thiamin, riboflavin, magnesium, phosphorus, potassium and manganese. And it's a good source of protein, folate, pantothenic acid and copper.
By the way, watercress isn't the only cress. Nasturtium (yes, the pretty flowers) is cress, and so is peppery hot garden cress and slightly bitter Korean watercress. Close in flavor to watercress, upland cress is thinner stemmed, making it perfect for salads.
The French use watercress to make a popular potato soup, and the English have popularized watercress sandwiches. Italian cooks add it to minestrone soup, and Chinese cooks add it to egg drop and wonton soups. Watercress Soup with Shiitake Mushrooms pairs the fresh green color and bright taste of watercress with the deep flavor and earthy tones of shiitake mushrooms.
Watercress is lovely served with other fresh greens, like the Bibb or butter lettuce in Lettuce Wraps with Watercress Aioli. Or try it in place of lettuce when making a BLT or topping a burger. Add it to scrambled eggs or a frittata, or toss it with grains, like the couscous in Couscous with Feta and Toasted Pine Nuts.
Because it likes cooler weather, watercress is at its peak from April through June.
Look for healthy green leaves and a fresh, spicy scent. Avoid leaves that are yellow and stems that are slippery.
Refrigerate watercress in an open plastic bag in the refrigerator for up to four days. (Some produce experts suggest wrapping the stems in a damp paper towel first.) Wash it in cold water, then blot dry just before using.
Watercress isn't a great keeper, but you can sometimes refresh it, once wilted, in a bowl of ice water.