
Cutting onions is one of the best ways to hone your knife skills fast. Onions are relatively cheap and so many recipes call for them that you’ll be well practiced and a sizzling success in the kitchen in no time.
Have you ever tried to chop an onion only to end up with a mish mash of pieces of varying shapes and sizes, and possibly bits of the outer paper-like skin stuck throughout?
And then when you attempt to cook it, some ends are burnt, some are raw and the rest are somewhere in between?
Aesthetics aside, unevenly hacked up onions don’t cook evenly and won’t distribute well in a recipe. It’s not pleasant biting into a big piece when you’re not expecting it.
Do your onion ring slices resemble a flat tire left on the side of the highway? Are your dices looking dicey?
If you don’t know where to begin with cutting onions, make sure you have a sharp chef’s knife (Here’s the one we use), then go grab a sack and follow this guide.
Cutting Onions 101: Don’t cry
It’s true that cutting onions can make you tear up. This happens when the cell walls are broken and emit a gas called s-oxide that irritates the eyes. You can minimize this from happening by:
- Using fresh onions
- Using a sharp knife to make clean cuts, thereby breaking fewer cell walls
- Refrigerating onions to slow down the gas emission
- Soaking onions in water to remove the gas completely
- Wearing safety glasses/goggles to block the gas
All of these suggestions will help, however, the faster you get at cutting, the quicker you’ll be able to move the onions away from your work area and your eyeballs.
In these demonstration pictures, a sweet onion was used, which has a higher water content and consequently don’t stay fresh as long as other varieties. You can already see the green, aka spring onions, sprouting in the center.

Sweet onions are great for beer battered onion rings and we recommend using them within a week of buying. Otherwise yellow or white onions typically have a longer shelf life and will make more uniformly round rings.
Prep for cutting onions: Remove the skin by Topping and Tailing
A common mistake is to try and peel the onion before making any cuts.
An onion has two ends, the top where the bud sprouts from, and the tail, which is the root end that is holding all of the layers together. By cutting off one or both ends, you’ll be able to easily peel of the skin.

You’ll always start by slicing the top off, also known as “topping” the onion.

If you’re slicing rings, you’ll want to “tail” or slice off the bottom as well.

Cutting onions the right way
How to slice onion rings
To prevent the onion from rolling away from you as you slice rings, you can slice a small sliver off the side going end to end as pictured below.


If not slicing into rings, cut in half at the onion’s equator. Keeping the root end intact will keep the layers from separating when dicing the onion.
You may find that your onion is starting to get soft in spots or go bad, but you can go ahead and remove those layers.
- Using your non cutting hand as a guide, place it on the onion near the end you’re slicing.
- Curl your fingers and tuck your thumb under them while applying downward pressure.
- Your knuckles will determine how wide your rings will be and guide your cuts to be at a 90 angle while also protecting your fingers from the knife blade.
- After each slice you’ll slide your guide hand back in even increments to make slices that are even in width. This will take some practice but you’ll notice your slices becoming more uniform with time.
- You can slice the onion perpendicular from the ends and make rings or halve the onion to make half rings.

Slicing Onion Strips
Take a halved onion that’s been topped and tailed, then slice it parallel to the root end to make onion strips as pictured below.


The difference between chopping and dicing
These words are often used interchangeably, but typically a chop is larger than a dice.
Chopping
You can slice strips and then cut those in half, and you’d have a rough or course chop as pictured.

Dicing
To dice, make several short cuts perpendicular to the flat side of the onion from one side of the onion to the other. Be sure to avoid cutting across the whole onion. Leaving the root end intact will greatly help with this.

If a recipe calls for “finely diced” onion, such as our fantastic guacamole recipe, simply make the spaces between your slices slightly smaller.
Next, turn the onion 90 degrees and make small slices parallel to the flat side of the onion until you’ve reached the root end. You now have a pile of diced onion.

What’s the difference between a dice and a mince?
Mincing Onions
A mince is a much finer dice. With a chef’s knife, rock the blade back and forth over your diced onions. Use the blade to scrape it into a pile and keep working the knife over the pile until it’s minced as fine as you like it.


Find a recipe, and start practicing!
As with anything in cooking, practice makes perfect. Find recipes that will force you to practice a lot, such as ones involving a mirepoix, and you’ll master slicing, chopping, dicing and mincing onions in a very short time.
Very informative.