Introduction: How to Cut an Onion (efficiently & Safely)
No one wants to cut onions for longer then they need to. So when a recipe calls for diced onion, I use this method so that I'm done in no time (& with no tears!).
I will say it took a number of years in my cooking life before I learned this, before that, onion chopping was on the least-favourite list of ingredients to prepare. I very much appreciate my friend taking the time to show this to me; now use it regularly(basically every time!).
Using this method so often means I can work quickly, while still being safe - since I know where not to put my fingers!
So with all that in mind I thought I would pass it on, as it might help someone else !
To give this a try, you'll need:
- Onion
- Sharp knife
- Cutting board
Step 1: The Dicing Technique
The technique is simple once you get the hang of it but it can be difficult to explain so the photos will be very helpful here. I've labelled them with the corresponding number so you can understand better.
- Cut your onion in half, down the centre. Work with each half the same way as described in the following steps.
- On your half onion, put the newly cut side on the cutting board so it is sturdy. Then cut off the tip of the onion off (BEWARE: don't cut the nub side side otherwise it will not hold together for you in the next steps)
- Peel and remove the thin papery skin from the onion
- Slice your onion length-ways (perpendicular to the nub). Make sure your cuts start as close to the nub side as possible without cutting all the way through. Repeat this over and over to create strips and leave about 1/2 centimetre spaces in between each cut (leave bigger spaces between cuts for a more course sized diced onion and smaller spaces if you want it finely diced)
- Slice your onion horizontally. Slowly cut your onion towards the nub with your knife horizontal to the cutting board. Again do not cut all the way through. (Pay special attention to your fingers here!). If you want a finer dice, you will want to do this twice (cutting equally into thirds)
- Cut off your diced onion. Next you want to cut down towards your cutting board again, parallel to the nub. As you do so your onion will come off in small cubes - diced and ready to use. Keep cutting until you reach the nub.
- Discard nub, and there you have your diced onion ready to use!
Step 2: Knife Safety
When you're cutting things so closely it is key to watch where your fingers are. At all times it will be important for your non cutting hand to to stay out of the knife's way. However, depending on which step you are on at the time, there are some easy ways to keep your fingers out of harms way. Some suggestions on how to do this safely are below:
- Cutting onion in half - use a flat hand with palm on top of knife
- Cutting length-ways into strips - hold onion on either side, with the knife underneath (making a bridge with your hand over the knife) while carefully inserting knife tip into the onion. Move the knife directly down towards the cutting board with your knife hand while holding the onion firmly.
- Cutting horizontally - hold onion on top with flat hand while knife hand slowly saws into the onion
- Cutting diced onion off - You will need to hold the onion together a you cut. make sure your fingers are a good distance from your next cut (sometimes people suggest to curl fingers towards your palm - but for this the onion needs to be held together as you cut). Start with your knife closer to the tip end (see photo) and then cut through the onion slowly using one smooth movement down and forward.
The key to staying safe is to:
- Pay attention to what you're cutting (distractions often end up in you cutting yourself)
- Work slowly - do not try to cut in a hurry, you will develop speed with practice but if you are just starting chop/cut at a pace you are comfortable with.
Step 3: Other Ways to Safely Cut Up Onions (+ Avoid Tears)
You don't always need to use a sharp knife cut an onion. When you don't need the onion to be diced (such as in some sauces) there are other ways you can cut onion with minimal handling.
- Peel your onion and grate it using the largest size on the cheese grater
- Note: I've found when grating you get a much higher release of oils which make you tear up.
- Remove the outer skin and nub and toss it in your food processor or blender for a quick couple of pulses
Tips to avoid tears
Onions often have the ability to make you cry as you start to cut them. Here are some tips to help you avoid the water works:
- Keep your onion in the fridge before cutting. A cold onion will release less vapours when you're cutting it
- Chew on some gum while you're chopping. I'm not sure how this one works, but it 100% does. Try it!

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12 Comments
6 years ago
The best way to avoid the crying while cutting onions, in my opinion, is to make sure you only cut onions with which you have not formed an emotional attachment.
7 years ago
It's not a good idea to chew gum while cutting onions. The reason, your eyes naturally tear up because they can't have the stuff onions release on them.
Reply 7 years ago on Introduction
What does chewing gum have to do with it?
Reply 7 years ago
I'm not really sure what it does, if that's what you meant.
7 years ago
This is the same technique I use, works very well. I tend to run my knife under water before I get into the final stages of cutting, helps eliminate the crying eyes syndrome ;-)
Reply 7 years ago on Introduction
Best way for me to avoid crying while cutting onions is to have my wonderful husband who is not affected by the "crying onion syndrome" cut all of my onions. One day he will not be around and I will then try this method and remember to rinse the knife before the final cuts.
7 years ago on Introduction
I find that squeezing an onion down on to the chopping board a couple of times makes the skin come off more easily and 'pre-explodes' the cry-making onion cells a little so you cry less. If you squash too much, the onion separates and becomes a sloppy mess.
7 years ago on Introduction
Cool Bro. Love it.
7 years ago on Introduction
Nice trick :)
7 years ago on Introduction
It is indeed one of the fastest ways to go about it. I took some cooking classes while in high school and this is the method they taught us.
7 years ago
A safer option is to cut the onion into quarters instead of halves. Then instead of doing vertical slits and horizontal slits (which is where most people make mistakes), you do vertical slits, roll it 90 degrees, and vertical slits again. Then you can put 2 quarters together to make a half to cut it just as fast as before.
7 years ago on Introduction
this trick look easier. helpfully yeah