If you haven’t already, please make sure you’re familiar with basic knife safety before starting this tutorial. (link)
Like onions, leeks are a type of allium. In fact, they taste rather like a soft, mild, onion. And they look like a giant, tough, spring onion! So if you’re already familiar with chopping spring onions (tutorial here), chopping leeks is quite easy.
Now it’s a step I’ve been known to skip with a lot of veggies, but it is important to wash your leeks. The reason is that the structure of leeks is exceptionally good at trapping small amounts of dirt. Because of this, you may find it easier to rinse leeks after chopping them.
To start chopping your leek, first remove about 1cm off the root end. Also remove the dried out ends of the leaves, and any dried out whole leaves. (Some people recommend removing all the dark green parts – while these are slightly tougher they soften when cooked, especially when slow-cooked.)
For slow-cooking, I recommend chunks of leek. Starting from the green end of the leek, simply cut off chunks about 2cm (a little under an inch) long. These chunks are perfect for roasts and casseroles, and they take about an hour to cook at Gas Mark 4 (180°, or 160° fan).
For faster cooking, slice your leek instead. Just like with chunks of leek, start from the green end of the leek. (This helps the leek stay together while you cut.) For most uses, I recommend slices about ½ cm thick, which you can pan-fry in 10-15 minutes. Thinner slices will cook faster.
When cooked, leeks become soft and translucent, just like onions do.
Leeks are great for giving a milder, sweeter, onion-y taste to dishes. They’re especially good with potatoes – why not try frying some sliced leeks in butter, and mixing them in with mashed potatoes? They’re also great in casseroles!