How to Cut an Onion: Guide to Dicing, Chopping, and Slicing Onions

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young woman cuts an onion

Are you preparing one of my favorite recipes – French onion chicken? Or chopping veggies for making a fresh summer salad? Both include cutting onions. And many of my readers would really like to avoid this step because onions are such a hassle to chop, and they also make everyone around cry. 

Hence, I am about to make your onion-cutting experience tear-free, fast, and easy. Before we jump to instructions, I want you to find your sharpest knife or take your blunt knives and sharpen them till they shine. This will make a big difference and let your seamlessly slice through the onion. 

Ready your knife, and let’s get down to mastering the skill of cutting onions. 

How to Dice an Onion Safely 

  • Use a sharp knife: Some say sharp knives are safer than blunt ones. This is because you slice through vegetables without putting too much pressure. Otherwise, you risk hurting yourself with a blunt blade. 
  • Cut with the center of the blade: The sharpest part of the knife is its center. So whenever you want to make a cut, it’s best to start from the center of the blade and not its tip. 
  • Protect your fingertips: When cutting, hold the onion firmly so that it doesn’t slide away. Make sure you keep your fingers curled on the onion with your knuckles almost touching the blade. 

Peeling the Skin the Easy Way 

To help you learn how to slice the onion quickly and tear-free, you need to know how to peel it first. The quickest way to do it is to:

  1. Place the opinion on the cutting board and take a sharp knife. 
  2. Hold the onion firmly with its ends facing the sides.
  3. Trim off the stem and the root with your sharp knife. Don’t cut off too big of a piece – instead, make a shallow cut and leave the root intact for the next step. 
  4. If you want to slice an onion, barely slice the root end. This way, it will be easier to slice the onion. 
  5. If you want to dice an onion, cut off the stringy root but leave the root intact.
  6. Cut the onion in half and peel the skin off from the two halves. 
  7. (Optional) If the first layer is too slippery and makes it harder to slice or dice your onions, you can remove it as well. 

Fast tip: To make a perfect cut in half, place your onion on its flat stem and slice through the root all the way down. 

How to Slice an Onion Into Strips

cutting an onion into strips

Now that you have two perfectly cut halves of an onion, you can get to cutting. Cutting an onion into strips will suit many recipes: salads, side dishes, and appetizers

Place one-half of an onion on the cutting board with your fingers clawed on it on the center of the onion. Start slicing its grain into thin, long slices. This way, your onion will release fewer sulfur molecules, which equals milder flavor, perfect for stir-fried dishes and soups.   

Another way to slice an onion is against the grain. Place your fingers near the root and start slicing shorter but more curved slices. This way, you will rupture more cell walls, and the onion will release more flavor. Slicing an onion crosswise will go well with salads and juicy burgers. 

How to Cut an Onion Into Wedges

Onion wedges will go well with crockpot dishes and various stews. Slightly bigger chunks of onion will absorb the flavor of other ingredients and blend well with chicken or beef. 

To cut an onion into wedges, place one of the halves on the cutting board cut-side down.  Make angle cuts around the onion to have about 5-6 equal-sized wedges. When cutting, direct the blade toward the center of the onion.  

How to Cut an Onion Into Rings 

Onion rings are an all-time favorite of mine. They must be the simplest to make. To chop onion rings, trim off the edges and peel the onion. Do not cut it in half. Instead, place your onion on the cutting board with the stem and root facing the sides. 

Next, chop off the stem just a bit and slice the same small bit from the middle of the onion so that your onion doesn’t roll away, and your next chop will form a nice, round ring. 

Start chopping the onion crosswise. The thickness of the onion rings is purely up to your preference. 

I like to make fried panko-breaded onion rings – they are crispy and simply such a delicious snack. And if you have some of them left (I doubt that you would!), you can add the remaining to a burger or a sandwich.   

How to Dice an Onion

cutting an onion into pieces

Dicing an onion is probably the hardest of all methods I describe here. As much as you would like to avoid dicing an onion, I have two ways to ease your work and some out-of-this-world recipes where diced onions are a must-have ingredient. 

Method #1:

  1. Take one half of an onion and place it cut-side down. 
  2. Make a horizontal cut through the half but stop at the root. Otherwise, your onion may fall apart. You still would be able to dice your onion, it will just be a bit harder.
  3. Next, make vertical cuts similar to the wedges described above but much thinner. 
  4. Finally, you want to slice the onion against the grain thinly. You will end up with thinly diced onion ready for a stir-fry dish or soup. Feel free to make thicker slices for recipes with coarse-chopped onions. 

Fast tip: Be careful not to cut the root since it hold the onion together when you slice it horizontally and vertically. 

Method #2:

This method is for those who can’t quite make the perfect horizontal cut without cutting the onion in half. 

  1. Take one of the halves and make vertical cuts toward the cutting board and not the center of an onion (similar to thick slices but without cutting off the root). 
  2. Divide the half into two pieces and another series of vertical cuts through the middle. 
  3. Lastly, slice the onion halves into pieces.

Fast tip: You can also make vertical cuts at an angle and make additional vertical cuts toward the board before slicing the onion into pieces.

I promised to share some of my delicious recipes that require diced onions, so here they are:

  • Tuna pasta salad – Tuna pasta salad is a nourishing dish for lunch and light dinner. It’s easy to prepare and requires only five ingredients you can find at home: mini pasta, peas, onions, pickles, and tuna. 
  • Twice-baked potatoes with caramelized onion – This recipe has many variations, and one of them includes sweet caramelized onions on top of mashed potatoes mixed with bacon pieces and cheddar cheese. 
  • Buffalo chicken dip – Great appetizer to surprise everyone at a house party. This dip consists of finely diced onions, minced garlic, cheese cubes, chicken broth, and a few other ingredients. Served best with crackers or pita bread.  

How to Mince an Onion in a Food Processor

Contrary to the previous cutting method, mincing an onion is the easiest and fastest way to cut it. Although it may not be the method you want to use universally for all of my recipes, some dishes require tiny pieces of onion. 

To mince an onion as finely as you can, prep your food processor. After you peel the onion and cut off its root and stem, chop the onion into quarters. Throw those quarters into a food processor bowl, run it by pressing the pulse button, and let the device do its magic. 

Fast tip: If you don’t have a food processor, alternatively, you can use a blender to finely grind onions.  

Tear-Free Onion Cutting Tips

Everybody like the smell of stir-fried onion, but nobody is a fan of cutting it into pieces. So, I decided to share my tips on how to chop an onion without crying:

  • Keep your onion in a fridge for at least 30 minutes before cooking. Cold temperatures will slow down the compounds’ activity, and you will have more time to cut an onion.  
  • Turn on a went or keep a window open. By maintaining air circulation in your kitchen, the compounds that an onion releases will not reach your eyes.  
  • Don’t cut the root. Throughout my cutting methods, I have stressed that it’s important to keep the whole root intact. First of all, it keeps the whole onion together, even when you make vertical and horizontal cuts. Secondly, the root is the only part that releases the most sulphuric compounds. 
  • Place the onion pieces into a container after cutting. If you are not planning on cooking onion right away, I would recommend storing it in a container. If you only cut one onion and not many, place the onion chunks side-cut down on the cutting board. 
  • Sharpen your knife. With a sharp knife, you will make clean, precise cuts and not rupture other cell walls when slicing or dicing an onion. Not to mention you will be able to cut your onion into pieces much faster than with a blunt knife. 
  • Protect your eyes with glasses or lenses. If you have goggles lying around, put those on! And if you wear lenses, they will also protect your eyes from released compounds.   

Frequently Asked Questions

Why do onions make us cry?

Have you ever noticed that onion doesn’t release any odor up until it’s cut? Well, there is a good explanation for this. When you make the first cuts into the onion, you disturb its cell walls that release certain compounds (lachrymator) that irritate the nerves around our eyes. The more you cut onion, the more cell walls you rupture. 

As if it wasn’t enough, when the compounds combine with tears, it produces another compound that starts to sting our eyes.

How to store onions?

After cutting an onion, you can either refrigerate it or keep it in a freezer. Onions stay fresh for up to 10 days in a refrigerator and up to 6 months in a freezer. 

I would recommend storing onions in a glass air-tight container. You may also place onion pieces into a resealable bag and a plastic container to prevent odor from escaping. As for a freezer, one resealable bag is enough to freeze onions.

Should I remove the center of an onion?

Removing or keeping the center of an onion is totally up to your preference. If you don’t like the strong onion flavor, you may want to remove it. However, for some recipes, adding the entire onion will give your dish an exceptional taste.

Which knife is the best to cut an onion?

Any sharp knife is good for cutting onions into pieces. I personally like to use the chef’s knife. It’s not too big but also not too short for cutting onions of different sizes. I find it easy to sharpen, too.

Final Word

Onions are rich in flavor and transform almost any savory recipe into an exquisite dish. I hope my methods helped you find a more convenient and faster way to dice your onions. 

If you have a better method or want to share delicious recipes, I would love to learn your approach to cooking with onions. 

Share your thoughts below in the comment setion.

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