With a more delicate and sweeter taste than onions, leeks look like large scallions, with very small bulbs and a long, white, cylindrical stalk of superimposed layers that grow into green, tightly wrapped leaves. They add a subtle flavor to dishes, without overpowering the other ingredients. A good source of fiber, folic acid, vitamins B6 and C, manganese, and iron, leeks are a wonderful addition to any meal. This cool-weather crop is easy to grow, with some leek varieties even thriving in containers!