How to Cut an Onion
Published February 24, 2021. This post may contain affiliate links. Please read my disclosure policy.
Cutting an onion is one of the most fundamental culinary basic techniques, so learn these foolproof procedures for perfect cut onions every time.
Basic cooking schools are so important to hone your skills while in the kitchen. If you’re looking to put your skills into practice then check out my techniques for How to Start a Fire or How to Truss a Chicken.

How to Cut an Onion
Learning how to cut an onion takes a lot of practice to perfect it. The best news is, onions are one of the most common ingredients used in recipes, so there should be plenty of opportunities for practice.
The most important aspect of properly cutting an onion is ensuring you have a very sharp knife. While you can use any knife, I recommend using your chef knife to cut onions. If your knife isn’t sharp you risk injury to yourself or others.
What Onions to Use
Any onion can be fabricated to your liking, but these specific onions are perfect for honing your cutting skills using this technique. Here are the onions you could use:
- Red
- Yellow
- White
- Sweet
- Shallot
- Garlic
How to Do It
Follow along with these procedures to learn how to properly cut an onion:
Slice the ends of the onion, slice it in half and then remove the outside peel.

Press your non-cutting fingers onto the top of a ½ an onion and press down. Next, starting from the bottom to the top make slices going through ¾ of the onion.

Now, starting from top to bottom slice down through the onion.

Turn the onion 90° and make several slices down to create your dice.

Make-Ahead and Storage
Make-Ahead: I am a firm believer in prepping things ahead of time so that the cooking process is seamless. You can slice onions up to 3 days ahead of time.
How to Store: Cover and keep in the refrigerator for up to 5 days. They only freeze well if you plan to use them in soups after thawing. They will hold in the freezer covered for up to 3 months.
Chef notes + tips
- The liquid, or milk, that secretes from onions works well for burns to your skin.
- In the video below you will see other ways to cut an onion outside of dice sizes.
- Alter the amount of space in-between slices to create small, medium, or large dice cuts.

Recipes to Use Them In
Check out the how-to video below, and be sure to follow me on Facebook, YouTube, Instagram, and Pinterest, and if you’ve had a chance to make this, then definitely drop me a comment and a rating below!
Ok, I am SOOOOO glad I found you and your videos online. I have always sort of dredded cooking. But watching and following your basics and then applying to your recipes and my passed down family recipes….I think I am seriously beginning to enjoy cooking! Thank-you so much!
Love it!
Chef, I searched your website for your video on knives and how to sharpen and couldn’t find it. Please share… thanks
it’s on YT.
I NEED a sharp knife! While I sharpen my own on a wet stone it is not always sharp! I’ll keep trying. A lot of GREAT info to know‼️‼️‼️
NO MORE TEARS!! Slice onions, then quick freeze. Once frozen, put in a baggie and store in the freezer. When you need diced onions, just grab a handful outta the bag and dice away.
I also quarter my onions, then thinly slice from the root. Make 1/3 turn, slice thinly again from the root, then dice from the end opposite the root. No danger of getting your hand sliced if you’re a bit clumsy.
Some people say that the sharper the knife, the less likely the tears will come. Hogwash, I say.
I’ve been watching your video and practicing my small and medium dicing. Thank you chef for showing good techniques. I am learning a lot from you.
my pleasure
My only way of cutting a lot of onions without crying is to wear swimming goggles! I’m not on camera and nobody’s looking so no harm no foul!
I used to always wear my ski goggles! Especially if I’m wearing mascara and don’t want it to run 🤣🤣🤣