How to Cut an Onion (& Why Different Cuts Actually Matter)

How to slice, dice, roughly chop, finely chop, and mince your way to onion greatness.

December 11, 2019

There are as many ways to cut an onion as there are to skin a cat. Actually, no, cutting an onion is way simpler than skinning a cat. Below, Nozlee explains if cutting an onion a specific way even matters (it does), why you might choose to cut it into different shapes and sizes (to control its cook rate), and how to do so the right way (“right” as in the way all your fingertips remain intact). 

But does it really matter how I cut an onion?

When Table for One columnist, Eric Kim, saw this article on the editorial calendar, he was proud to report to the editorial team that he had no method whatsoever. He slices an onion one way, turns it around, slices it the other way, and there you go, chopped onion.

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But let's use this Braised Onion Sauce as a case study. In the recipe, Kenzi calls for onions to be sliced into 1/4”-thick half-moons. But, let’s say, we cut 1”-thick slices instead. The cut surfaces exposed to the pan—or, the parts of the onions that will soften, brown, and caramelize quickest—would make up a much smaller percentage of the onions in the pan. After braising for an hour, the centers of each onion slice would be cooked less than if they had been cut to ¼”-thick slices. Conversely, if we cut 1/16”-thick slices, the onions will caramelize much quicker in the prescribed hour. The final texture of the sauce would be jammier, closer to a puree. So, how you chop does kind of matter.

That being said, chopping an onion isn't rocket science—in fact, it's one of the first things you learn in the kitchen. Whether you're a first-timer or an old hand, today we have a primer on the various ways to chop an onion: dicing, slicing (two ways!), and a coarse chop. Our co-founder, Merrill, who seems to be in the same onion boat as Eric, said: "It doesn't really matter how you cut an onion, but if you don't do that right, why do anything right at all?" We agree.

One thing we don't have an answer to is how to avoid teary eyes while chopping. Advice runs from the sensible-sounding (keep the root end, which contains most of the compound that makes your eyes water, as intact as possible) to the silly (chop with a piece of bread in your mouth, or wear special goggles).

Let's get chopping! the different cuts are:

Dice (Large, medium, and small)

As seen in: Individual Sweet Potato Gratins with Crème Fraîche, Onions, and Bacon

When you're stumped for what to make for dinner, dicing an onion is never a bad place to start. By the time you're done, you're likely to have an idea about whether it'll be soup, a frittata, or anything else. Whether large, medium, or small dice, the approach is very similar. Diced onions, like roughly chopped onions, are used for a prominent, but consistent onion flavor and texture (chunks of similar-ish shape and mass are more likely to cook at the same rate and in the same way). Sharpen your best knife—a sharp knife is actually less dangerous than a dull one, which you can easily lose control of— and let's get started.

1. Peel and Prep. First things first: halve the onion through the root and tail ends. Chop off that tail end and discard, then remove all traces of papery skin.

2. Cut Horizontally. Being careful not to cut your hands, make 2 to 3 horizontal cuts through the onion, stopping before you reach the root—again, a very sharp knife helps with this! What's the point of this step? You're cutting through the curvature of the onion's surface, making for evenly square pieces of onion when you finish.

3a. Cut Vertically. Cutting from just before the root to the tail end, make 5 to 6 straight cuts perpendicular to the horizontal ones. (Don't worry too much if slices on the side start to fall off because your cuts are too deep; hold them together with your fingers and keep going.)

3b. Or, Cut Radially. Our Genius Recipes columnist, Kristen's brother, Billy, prefers radial cuts when dicing his onions—i.e. angling along with the curve of the onion—which he claims makes for a neater dice afterward. We tried it and found the results to be more or less the same, but it certainly doesn't hurt to get geometry involved!

4. Ready to Go! After being cut every which way, this onion is ready for its final destiny.

5. Final Dice. Starting at the tail and moving toward the root, cut across the onion to make tiny, evenly-sized pieces of onion: a true dice. (I look like I'm about to cut my fingers off in that first photo. Rest assured that I still have all 10 of them.)

6. Discard The Root. And that's it—sauté-ready diced onions.

Slice (Half-Moons)

As seen in: Cider-Braised Pork Shoulder with Caramelized Onion and Apple Confit

There are two ways to slice an onion. The first is easiest, and it's what you look to when pickling onions, topping a pizza, or slicing up chili garnishes. The half-moon shape gives the "face" of each onion slice maximum surface-area, and so is also conducive to browning.

1. Peel and Prep. The first steps are the same: halve the onion, cut off the tail end, and peel it. Rest the halves flat-side-down.

2. Slice Away. Pushing the knife down and forward, make evenly-spaced slices, finally ending at the root. If the recipe calls for anything thinner than 1/8” slices, I will usually switch over to a mandoline. 

Slice (Radial-ish)

As seen in: Braised Onion Sauce

When you're looking to caramelize a batch of onions— to top mashed potatoes, garnish polenta, or make classic French onion soup—you should slice a little differently. The method above produces unevenly-sized slices, which means that after 30 minutes or more of slow caramelization, some of those slices will have entirely dissolved while others will still have their shape. For even cooking, it's best to slice a little differently: just turn your onion a quarter turn before going at it.

1. Peel and Prep (and Cut Off the Root End). For this preparation, you'll want to cut off the root end of your onion as well when prepping it. Then with the root and tail parallel to your knife, start at one side and start slicing away.

2. Ta-da! See? Same-sized slices ready for a long, slow session in the skillet.

Rough Chop, Fine Chop, and Mince

As seen in: Traditional French CassouletCreamy Tahini Potato SaladSausage Stuffed Mushrooms

Sometimes, the size and shape of your chopped onion doesn't matter so much, like when making kebabs or chicken stock. Like half-moons, this is another cut conducive to caramelizing (the multi-facetedness of each rough chunk maximizes surface area). We saved the easiest preparations for last!

1. Peel and Prep. The first steps are the same: halve the onion, cut off the tail end, and peel it. Rest the halves flat-side-down.

2. Like Dicing, But Not. Take everything we said about slicing vertically and horizontally and toss it out the window: simply make 3-4 cuts from root to tail, then 3-4 cuts from side to side. For finely chopped onions, make 6-8 cuts each way, and for minced onions, fan-chop the finely-chopped onions until you have tiny 1/16" bits.

This article was originally published in July 2012, and has been updated with relevant information.

What's your best anti-onion-crying technique? Let us know below in the comments.

See what other Food52 readers are saying.

  • IWearTheHat
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I'm Nozlee Samadzadeh, a writer, editor, farmer, developer, and passionate home cook. Growing up Iranian in Oklahoma, working on a small-scale organic farm, and cooking on a budget all influence the way I cook -- herbed rice dishes, chicken fried steak, heirloom tomato salad, and simple poached eggs all make appearances on my bright blue kitchen table. I love to eat kimchi (homemade!) straight from the jar and I eat cake for breakfast.


IWearTheHat November 25, 2020
I agree with some other viewers that commented; this video was more than just "cutting onions" and if that's all some got out of it then they truly missed the interaction between the master and the host or just didn't care, I guess. I watched Josh smile frequently throughout the video as he learned something each time Jacques held a knife and demonstrated, and it was interesting to see from Josh what is being taught today compared to how Jacques learned and practices. Heck, I learned how to peel a few other things in addition to things like thumb placement, etc. I enjoyed the video and the content very much; "heartwarming" is how I would describe seeing old school and new school working together and discussing.
jenzip November 25, 2020
So what an HONOR to cook with Jacques. That was an excellent video and I immensely enjoyed it. However, I couldn't find a way to watch it with subtitles? I have a few deaf friends, and so now I prefer to watch things with subtitles, so, just a thought for you guys at Food52. Thanks!
jmohns November 25, 2020
Master chef Jaques Pepin is the premier teacher. (Too bad the host didn't know that.)
holly M. December 11, 2019
♥️ this video for so many reasons: educational, emotional, enjoyable. Thank you!
IWearTheHat November 25, 2020
Zeelo May 7, 2015
Elizabeth J. March 28, 2015
re cutting onions without crying: keep your mouth shut and stand up straight. This tends to be good advice in many situations -- but it keeps your head, nose and eyes as far as possible from the onion. The candle idea makes sense - it burns off the gas before you inhale it, but gathering candle, holder and match would take me longer than cutting the onion. Interesting to hear all the methods people have found helpful if not perfect.
Stacey B. October 27, 2014
The only "scientific" way to not have onion tears is to refrigerate the onions before cutting them (I think I heard this from Alton Brown).
tia December 11, 2019
I use this trick and it works. That and a really sharp knife (mandolines are for suckers, in this case, they're never sharp enough). If I'm doing a LOT of onions, I'll sometimes set up a fan blowing across the work surface to blow the fumes away, which also works, but makes the whole house smell like onions.
Terrie A. September 14, 2014
I light a candle while cutting onions. I've been doing this forever, and always assumed it was common knowledge. The fact that no one suggested it before me makes me wonder if it's just an old wives tale, and the mere power of suggestion has made it effective for me. Anyone else use this trick?
Michael G. September 12, 2014
I keep the root and skin attached after I slice the onion through the top to the root. Fold the skin back, and it acts as a built-in handle.

According to The Help, holding a wooden match in your teeth prevents crying. I've not tried it.
chris January 16, 2014
There are two methods I like for slicing onions without tears. One is to place as much distance as possible between the onion and my eyes by cutting the onion on a low surface, such as a dining table versus a counter top.
The second method is to place the onion to be cut on a cutting board. Use a cutting board with slots for draining water. Next run a small drizzle of water over the onion while cutting. This works best. Do not allow the water to run too fast or your cutting board may not drain fast enough and you will have a bit of a flood. Happy onion cutting !
Rod May 25, 2013
wowwwwwwwwwwwwww I am surprised you still have 10 fingers.... I hope you are not a qualified chef... if so who taught you that
Abby May 22, 2013
I'd suggest a embedded video next time - much more useful, and elegant presentation. Unless your objective is to take up visual space, which this certainly does. Also, is your market people who have never cooked before? Cutting onions...really? Okay, if you say so, but I'd make put this under a tab called Kitchen Basics so you don't bore a more experienced audience. I like the concept of the website, but the content is lacking.
Jonathan H. May 21, 2013
Best onion tear prevention?
First and easiest, use a sharp knife. It damages fewer cells, so less of the offending gas is produced, so there are less tears.
You should also ventilate the kitchen. You should do that anyway to handle the inevitable occasional smoke in there.
Also sweet onions produce far less of the offending gas, and they caramelize easily, if that's what you're looking for.

Jonathan H. May 21, 2013
None of these is the best and easiest approach. With one simple method (not gadget), you can have a mince, thin strips (julienne) or evenly cut dice. With ease.
As with these others, begin with peeling. Then trim away any green or brown at the top. Cut away most of the root, but leave the very bottom intact. It will make cutting easier.
Slice the onion in half from the top/green end to the bottom/root end.
Here's the cool part. Take one half and slice it lengthwise, radially.
Is that confusing? Make several slices from the outside towards the center.
To be more specific, lay your knife almost horizontally at just above your cutting board, and slice the onion from the round outer peel side towards the core. Try to make this slice, and every slice until you've gone all the way around, reach all the way to the center of the core.
So from here you would turn your knife a little bit towards vertical, and make another slice to the core.
With just a little practice, you will be able to slice one half or one quarter of an onion like this easily, depending on the size of your hands and the size of the onion.
At this point you have thick or thin slices, depending on how you cut. You tried to make them even, how'd you do? It's up to you and what you want from this onion. Do you want big slices to cook with liver? Or do you want a fine mince for topping a fish taco (use purple for this)?
Anyway, onions are great, and if you now just cut crossways, your slices become a dice.
This method is really easy. People will be impressed with your knife skills.
You can apply a very similar method to carrots, celery, potatoes, anything.
Peter J. May 19, 2013
I have found keeping onions in the fridge reduces the amount of gaseous compounds released, tears are a thing of the past if you get the job done fast !
Henry B. May 19, 2013
Your finger postioning is dangerous - you appear to realise this. Curl your fingertips in under the length of the finger, and use the broad width of that santoku to butt up against the shortened fingers .... raise and lower the santoku against the 'fence' of the fingers. The way I see your fingers here, it's only a matter of time until one gets nicked, or worse. As for tears ..... just keep working, they don't hurt and they don't last long.
max H. May 18, 2013
No joke, I wear my scuba mask. , yes with the snorkel but I don't use it. Looks ridiculous and works.
judy H. April 24, 2013
When I cut up onion I strike a match blow it out and put it between your teeth. I buy the long kitchen matches.
BlueLineGal September 25, 2012
Best anti-onion-crying technique? I've found that breathing through the mouth (and not through the nose) while chopping prevents watery eyes. Perhaps because you inhale more of the onion's gases through the mouth (versus nose) before they reach your eyes or inhaling through the nose draws the gas closer to the eyes, thus creating more irritation.
Pegeen July 11, 2012
Goggles, for sure (or an old pair of sunglasses). I've tried everything else except contact lenses.