Here’s what you need to know.

Leeks look a lot like green onions, but they’re not green onions. So what are they—and what do you do with them?

What Are Leeks?

Leeks 2 Getty 12/19/19
Credit: Creativ Studio Heinemann/Getty Images

Creativ Studio Heinemann/Getty Images

A leek is a vegetable in the Allium genus, which also contains onions, green onions, garlic, shallots, scallions, and chives. 

Instead of forming a bulb (like an onion), the edible part of a leek is a made up of a cylindrical bundle of leaf sheaths. Because of its celery-like shape, this bundle is sometimes called a stem or stalk. However, that is incorrect.

An ancient food, the leek’s origins can be traced back to central Asia. It was also commonly eaten by the Egyptians, Greeks, and Romans.

Perhaps more than any other culture, however, the leek is associated with the Welsh.

So how did it come to be one of the national emblems of Wales? The leek was apparently essential to the country’s victory during the battle of Heathfield in 633 C.E.

As one version of the story goes, a celtic monk named David persuaded the army to distinguish themselves from their enemies by wearing leeks in their helmets. (To be fair to David, this wasn’t that weird of a suggestion—the battle was happening in a leek field).

To everyone’s surprise, this identification tool helped them win the battle.

Another version of the tale holds that it was King Cadwaladr of Gwynedd’s idea to don the vegetable during the skirmish.

In any case, the leek is still a symbol of good luck in Wales. It’s worn annually by Welsh people on March 1 to celebrate St. David’s Day.

Leeks Getty 12/19/19
Credit: Benita Kuszpit Wojnarowicz / Eye/Getty Images

What Do They Taste Like?

Leeks taste like onions, but milder and slightly sweeter. This makes them a welcome addition to all sorts of dishes. For instance, they’re commonly used in soups, casseroles, and salads.

When raw, leeks are crunchy and firm. Frying intensifies this crunchiness. When they’re boiled, however, leeks become soft and even milder in flavor.

Leek Substitutes

If you don’t have a leek on hand, don’t panic. You can substitute:

  • Green onions. They’re not quite the same, but this’ll be your best bet.
  • Shallots. Like leeks, shallots are mild in flavor.
  • Regular onions. Just use a smaller amount than the recipe calls for, as onions will pack more flavor than leeks.

Leek Nutrition

Good news, leek lovers: The veggie is super healthy. Here are some nutritional highlights:

  • Leeks are nutrient-dense, which means they’re high in vitamins and minerals but low in calories.
  • They’re a good source of vitamin A (which is good for vision), vitamin K1 (which supports blood clotting and heart health), and vitamin C (which is essential for a healthy immune system).
  • Since they’re relatively high in fiber, leeks can support a healthy digestive system.
  • A rich source of antioxidants, eating leeks may help prevent cancer, heart disease, and diabetes.
  • The sulfur compounds in alliums may promote brain function and lower blood sugar levels.

How to Prepare Leeks

Cutting Leeks Getty 12/19/19
Credit: Sam Van Den Brandt / EyeEm/Getty Images

Sam Van Den Brandt / EyeEm/Getty Images

First things first: When you’re shopping, look for crisp and firm leeks that are light green and white. Avoid them if they’re withered or yellowed. Pro-tip: The smaller the leek, the more flavor it probably packs.

How to Cut

To cut a leek, you must first trim the roots and chop off the tough, dark green part.

For most recipes, you’ll do as follows: Slice the “stalk” in half lengthwise, before cutting into thin slices.

How to Clean

Like anything that grows in soil, you need to wash leeks thoroughly before you eat with them. This is a bit easier to do after the leeks have been cut. All you need to do is place the small pieces in a bowl of clean water—the dirt will settle at the bottom.

If you’re using the whole vegetable, however, rinse it until all visible dirt or grit has disappeared down the drain. Make sure to fan the layers while the tap is running to ensure that you’ve reached every nook and cranny.

How to Cook

Leeks are quite versatile, and you can cook them the same ways you can cook other alliums: They’re delicious sautéed, boiled, fried, roasted, braised, or enjoyed raw in a salad.

Just make sure not to overcook leeks, as they can easily become mushy and unappetizing. Add them into soups toward the end of cooking, not the beginning.

Leek Recipes

Skillet Chicken Pot Pie with Leeks and Mushrooms
Credit: Victor Protasio

Victor Protasio

Ready to try your hand at cooking with leeks? Check out some of our best leek recipes ever: