How to Cut an Onion (How to Dice, Mince, and Chop Onions)

Wondering how to cut an onion? So many recipes call for a bit of onion, and I very much approve of that! Whether you need diced onion, minced onion, or chopped onion, you need to know how to do it properly. Learning how to chop an onion is one of those basic cooking skills that will always come in handy. I’ll show you how to dice an onion, how to mince onion (plus the difference between the two), how to chop onions, and how to store cut onions!

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How to Cut Onions

Learn how to cut an onion, how to dice an onion, how to mince onion, and how to chop an onion. Basically, no matter how you want to cut it, you can learn it right here!

I love onions! I mean, I really love, love onions! They’re one of those ingredients that is so easy to add into dishes, and they always add so much extra flavor.

But before you can use them, you have to learn how to cut an onion…that was a major stumper for me in the beginning, but now I’ve figured out the best way to chop onions and it’s so easy!

I love red onions in salads, Vidalia onions for grilling, and sweet yellow onions for almost everything else I cook. I’m also learning to use leeks, shallots, scallions, baby onions and so many other types of onions. 

I wasn’t always a fan of onions (I know, crazy), but learning how to saute onions and caramelize onions changed everything! Sautéing onions in a little butter (for the flavor) and olive oil (to prevent burning) until translucent tenderizes and brings out the natural sweetness of this perfect ingredient. Now I’m hooked!

Cutting onions seems like such a simple thing, but when you’re new to cooking, none of those cooking terms makes sense! I’m lucky I had my mom to help me figure this stuff out, so now I’m passing all that glorious information on to you.

What’s the difference between diced, minced, and chopped onions?

Want to know how to cut an onion? Then you’re going to need to know the difference between diced onions, minced onions, and chopped onions. The best way to cut an onion depends on the recipe, so it’s good to know all three. This tutorial includes info for all three, so I’ve got you covered!

• Diced Onion: When a recipe calls for diced onion, you should have small pieces about 1/4 – 1/2 inch. Diced onions are best for mixing into all kinds of dishes. You’ll know they’re there, you’ll taste them, but there won’t be large chunks in every bite of your food.
• Minced Onion: Minced onions are about as small as you can get. It’s the same as dicing, but just much smaller, less than 1/2 inch in size. This works for recipes where you want the flavor, but you don’t really want to know they’re there. (Perfect when you’re cooking for someone who “doesn’t like onions”).
• Chopped Onion: Chopped is a more general term, which just refers to cutting an onion less precisely than you would with diced or minced. These pieces will be larger, and could essentially be any size that works for your recipe. Chopped onions are great for soups and stews because they can hold up while cooking in the broth. This is also a good way to cut onions if you really want it to be a noticeable part of the dish, so that you get plenty of onion flavor.

How to Peel an Onion

Before showing you how to cut an onion, you’ll need to peel it.

Start by slicing about a ½ inch off the top/ends of the onion.

Then remove any papery skins–there will usually be a couple of layers of this to peel off. The second layer might require a bit more work than the first. Pierce into the onion with the knife and create a shallow slice to help remove the rest of the papery skins.

How to Cut an Onion (Step by Step)

Before this wonderful vegetable can be used, it usually has to be chopped, diced or minced. So this is where I show yo how to cut an onion! I have seen many methods of preparing an onion, but this method is the one that works best for me.

Whether you chop, dice, or mince an onion, the process starts the same. Grab your cutting board and a sharp knife, then slice about 1/2 inch off the end/root of the onion. Remove those papery skins and any unusable layers (see above for details on how to peel an onion).

How to Dice an Onion

After peeling the onion, cut it in half and lay the halves flat-side down on the cutting board.

Use your knife to cut across the onion in 1/2 inch slices.

Then turn the onion and hold the cut layers together. Going in the other direction, cut across again in 1/2 inch slices. Repeat with the other half of the onion if needed, or keep it in tact and store it for later.

This is what diced onions will look like–aim for this general size, though they don’t need to be perfect.

How to Mince an Onion

Same as dicing an onion: peel the onion, then cut it in half and lay the halves on the cutting board, flat-side down.

Cut across the onion the same as you did above, but make 1/4 inch cuts to mince (or smaller if the recipe calls for a finer onion).

Turn the onion and hold the slices together. Then moving perpendicular to the slices, cut 1/4 inch slices again.

How to Chop an Onion

Chopping an onion is much less precise and can be done in a variety of ways. However, I typically cut the onion the same way as if I were dicing or mincing, just in larger pieces.

After peeling and cutting the onion in half as above, lay the flat side on the cutting board.

Cut in one direction in whatever size pieces you want. 3/4 inch is a good standard chopping size for a recipe that doesn’t specify otherwise.

Then moving in the other direction, cut again in 3/4 inch slices.

This is what roughly chopped onions will look like.

How to Cut Onions Without Crying

Most of us know that cutting onions can often lead to tears. Whether you’ve seen it on TV or experienced it yourself, it’s true that onions can make you cry. This is because onions release an irritant that affects our eyes. But don’t worry, you can actually get through the process without tears!

• One of the main ways to avoid crying is to keep cut ends of an onion faced away from you. So if you’re facing the cut halves down on the cutting board as I mentioned, that will help a bit.
• Using a properly sharpened knife will cut into the onion better, and cause less of that chemical irritant to be released. 
• Don’t touch your eyes or your face directly after chopping onions. Make sure you thoroughly wash your hands afterwards.
• As soon as you’re done cutting, set the onions away from you until you need to add them into your dish.
• Chilled onions will usually be less of a problem. So let the onion sit in the refrigerator for a bit before cutting.

How to Store Cut Onions

When you first buy onions, store them in a cool, dark pantry or cabinet. They will usually keep for 3-4 weeks if stored properly and kept dry. This is BEFORE cutting them.

Once you’ve cut the onion, you’ll need to store it differently. Here’s how to store cut onions:

• Place any diced or minced onion pieces in an airtight container, in the refrigerator.
• Chopped onions and larger pieces can be stored in reusable containers or resealable bags.
• If you have large uncut pieces of onion, you can also wrap them in plastic wrap. (For example, if you only cut half the onion, wrap the unused half and keep it in the refrigerator.)

Once an onion has been cut in any way, it needs to be stored in the refrigerator. It helps to keep onions in separate drawers so that other vegetables don’t get that oniony smell or flavor. Cut onions should be used within about 7-10 days.

How to Pick a Good Onion

Before you cut an onion, you have to pick the right one. Picking a good onion is fairly simple, though.

Choose one that is firm, unblemished, and unbruised. Look for onions that have tight, dry, tissuey skins. It also helps to smell them: if it has a strong onion scent, it probably isn’t very sweet. But typically this will be based on the type of onion you’re using. 

When picking a good onion, avoid any that: have soft or wet spots, are sprouting or decaying, or have noticeable moisture or discoloration.

That’s it! Learning how to cut an onion is really that simple. Diced onion, minced onion, chopped onion, it doesn’t matter. It’s all so easy. Now you can start sneaking these little flavor cubes into your culinary creations (and if you are cooking for someone that hates onions, they never have to know).