Knife Skills: How to Cut Scallions

Depending on how you cut them, scallions can be used as a chunky vegetable in a stir fry or on the grill, or they can be used as a garnish for any number of dishes.

But slicing a scallion properly is more than just for looks. The way you slice a scallion and the sharpness of your knife can have just as big an impact on its flavor as it does on its appearance. This is because scallion cells, like the cells of all alliums (that is, vegetables in the onion family such as onions, shallots, garlic, and leeks), scallion cells contain chemical precursors that combine to form the pungent, sulfurous compounds known as lachrymators once those cells are opened and their contents are released. These are the chemicals responsible for giving alliums their pungent aroma and tear-inducing properties.

In moderation, this can be a good thing. But if you release too many of those precursors, scallions can become so powerfully pungent that their milder, sweeter aromas are overpowered. A dull knife or poor technique is more likely to crush and rupture more scallion cells than a sharp knife and proper technique.

So how do you cut scallions to keep these pungent flavors at bay and keep them looking pretty? The key is to use a very  sharp knife (watch my knife sharpening video here), and to maximize horizontal motion rather than vertical motion.

Think slice, not chop.

Slicing Scallions

To do this, I employ a technique called the back slice; Rather than moving your knife up and down in a chopping motion, instead you start by holding the scallions in your non-knife hand, forming a claw with your fingers so that your fingertips are tucked back safely out of the way of the kniw. Then you place the tip of the knife on the cutting board so that the heel of the knife is lined up with the scallions and the flat side of the blade is pushed against the knuckles of your non-knife hand.

From here, you draw the knife backwards, keeping the tip of the blade firmly against the cutting board and relying on the angle of the knife to do the cutting for you .

Depending on the angle at which you hold the scallions, you can get round slices when cutting perfectly perpendicular to their length, or elongated slices by hold the onions at a bias.

Store sliced scallions in a container of water in order to keep them crunchy and fresh, and to ensure that they don't get too pungent, which can happen if you let sliced scallions sit for too long.

The sharper the angle of the bias, the more elongated the scallion slices will get until eventually, when your knife is held parallel to the scallion's length, you get what I call scallion hairs.

Scallion Hairs

 To cut scallions into thin hairs, start by cutting them down into manageable lengths, about two inches long. You can use the greens or whites to make scallion hairs.

Next, you can simply slice the scallion segments lengthwise as thin as possible, but for an easier time and cleaner-looking hairs, it helps to slit the scallion open lengthwise and flatten out the layers and stack them so you can get cleaner lengthwise cuts.

Once the scallions are sliced, they won't curl much. Storing them in cold water for a few minutes (or up to overnight) will plump them up and exaggerate their natural curvature, which will give them plenty of body and bounce (like hair from a commercial in the 90s).

Storing Scallions

Whole scallions can be stored wrapped up in a compostable bag for a few days in vegetable crisper, but they can be kept for longer if you wrap them in a damp paper towel first before bagging them in order to keep them plump and crisp.

Some folks will tell you that you can take the bottoms of scallions, put them in a glass of water, and that fresh scallions will grow out the top. While technically accurate in that the scallion bottoms will grow in a cup of water, I don't recommend doing this for two reasons.

The first is that in order to do this, you need to leave behind a good bit of the scalliion whites, which are the sweetest, mildest, and most pleasantly flavored part of the scallion.

More importantly, the scallion that grows back in a glass of water will be significantly less flavorful than the original scallion was, as there are no new nutrients for it to build itself with other than the trace minerals found in the water. Flavorful produce needs good organic soil (in the carbon-y and nitrogen-y sense of the word)!

I use up my scallions and buy fresh ones when I need them.