How To Cut An Onion The Right Way

Alright. You need to know how to cut an onion correctly. None of this smashing your knife into it until you roughly get the size you want. Let’s learn how to do this right. It will save you time. It will result in a more consistent product. It’ll make you more attractive and, your mother might finally be proud of you.

Have you ever been cutting an onion for a recipe, unsure of what you’re doing, tears streaming down your face, on the verge of a mental break down because your Julienne is starting to look more like triangles? Or maybe you don’t even know what a Julienne cut is.

Either way, we have the solution to all your onion-related questions. Whether you want to know how to stop crying while cutting onions, how to dice an onion in under a minute, or how to make Micheline star-worthy cuts, this blog will explain everything you need to know.

How to Cut an Onion Without Crying

Have trouble with your eyes watering when you cut onions? The simple answer is that your knife is too dull. Make sure to hone your knife before each use. Additionally, wash and dry your knives quickly after finishing cutting onions, as onions are acidic and will dull your knife if left dirty. Buying high quality knives and regularly sharpening them is the only way to prevent the teary eyes. If you have questions about how keep your knives sharp or how to select proper knives for your kitchen, check out our article on how to sharpen a knife.

What Knife to Use When Cutting an Onion

Knife choice is critical when approaching an onion. We won’t get too into kitchen knife skills in this particular article, but here are the things you want in a knife in order to cut onions.

You want a blade long enough to cut through the entire onion in one motion. You also want a knife that is tall enough that your knuckles will not hit the cutting board when making cuts. Finally, you will want a knife with a thin spine. Onions are soft so an extra strong thick spine is not needed. The added mobility of a thin spine knife is a major benefit here. 

While there many options available, there are only a few that really excel in this application. The knives you want to use are a nigiri, chef’s knife or santoku. 

Anatomy of an Onion

The first thing you need to understand when approaching an onion is the anatomy of said onion. Luckily, this is a very simple produce to understand. There are three things you need to know to be an expert. You need to know where the stem is, where the root is, and how the grain runs. These are all related and easy to understand.

The stem of the onion is what would be on top while the onion is growing. It is the end that comes to a fine point and is covered in the onion skin. The root is located on the opposite side from the stem. The root usually has some dirt on it and small roots still sticking out of it while not having skin on the root itself. Finally the grain runs from the root to stem.

This is all important to achieving the proper cut of your onion. Congrats, just by reading this you have taken the first step in knowing how to cut an onion.

Julienne vs Half Moon

Upon first view, a Julienne and half moon cut seem to be the same. However, they are different in some critical ways.

The difference is in the grain structure; the Julienne cut is with the grain while the half moon is sliced against the grain. This achieves different end results. A Julienne maintains its structural integrity through the cooking process and adds more texture to the dish, while a half moon is the opposite. Half moons will break down easier in slow cooking processes and be easier to bite through in raw applications. 

How do you know which to use when? Well of course, it depends, but here are some things to consider.

The finished product will determine what cut will work best. Long cooking processes like caramelizing onions and French onion soup need a Julienne cut to maintain the onion in distinct pieces. Meanwhile, if you want a soup to have onion flavor without long stringy pieces inside, a half moon is the answer.

If you are still confused about your specific application, try one and experiment. That’s the joy of cooking; we get to experiment and make our dishes in new ways. 

Types of Onion Cuts

Onion Rings

The easiest of the ways to cut an onion. This cut is used mainly when making deep fried union rings, however, there are other uses as well.

To cut an onion into rings simply:

1. Cup the stem off the onion and remove the skin
2. Chop large rings against the grain of the onion making 2-3 cuts
3. Separate the slices into individual rings
4. Enjoy 

Half Moons

Half moons are another simple way to prepare your onion. 

Used when you want long strips of onion that do not stay together super strongly. Uses include slices for cheeseburgers or hot dogs, salads, stews, and sauces where you want the onion to almost dissolve into the sauce.

How to Cut Half Moons

1. Remove stem of onion
2. Slice onion in half through root 
3. Remove skin of onion
4. Slice onion against grain as thin as possible
5. Enjoy

Julienne

Julienne onions are easy to mistake with half moons but there are important differences. While the general shape is similar, their uses are very different. As discussed before, Julienne cut is used when you want the onion to maintain its structural integrity throughout the cooking process. Uses include caramelized onions and stews where you want the onion to maintain its structural integrity. 

How to Julienne an Onion

1. Remove stem of onion
2. Slice onion in half through root 
3. Remove the root of the halves 
4. Remove skin of onion
5. Slice onion with the grain
6. Enjoy

Rough Chop

A rough chop is the beginning of the fun when it comes to cutting an onion. This cut is very cost efficient as it uses nearly the entire onion; there is little to no waste. This cut is very versatile and it’s a similar process to the dice and mince that we will discuss later. Uses include blended sauces, rustic style recipes, and anything going into a food processor. 

How to Rough Chop an Onion

1. Remove stem of onion
2. Slice onion in half through root
3. Remove skin of onion
4. Place slices with grain of onion without cutting through completely, approx. 3/8 inch wide (strips should still be attached to the root)
5. Place a horizontal slice halfway up the onion without cutting through completely
6. Slice onion against grain approx. 3/8 inch cuts to stem
7. When the onion gets too thin to slice again, tip onion onto the face of the last cut. Proceed to place slices until you get to the stem
8. Chop the remaining onion that’s adjacent to the stem
9. Enjoy

Diced 

Diced onion is probably the most common use of an onion. While it works great on nearly every application most people look like they are playing wack-a-mole with their knife. Here is how to truly chop an onion the correct way. Uses include salsas, salads, sauces and sautéed onions

How to Dice an Onion

1. Remove stem of onion
2. Slice onion in half through root
3. Remove skin of onion
4. Place slices with grain of onion without cutting through completely, approx. ¼ inch wide (strips should still be attached to the root)
5. Place 2 horizontal slice halfway up the onion without cutting through completely
6. Slice onion against grain approx. 1/4 inch cuts to stem
7. When the onion gets too thin to slice again, tip onion onto the face of the last cut. Proceed to place slices until you get to the stem
8. Chop the remaining onion that’s adjacent to the stem
9. Enjoy

Fine Dice

Fine diced onion is a true test of your knifework skill. While the process is the same as a rough chop and dice, the care and precision needed is increased. Showing off a quality fine dice will impress all your guests and make your meals worthy of being posted. Uses include garnish, burgers, salsas, chimichurri, and salads.

1. Remove stem of onion
2. Slice onion in half through root
3. Remove skin of onion
4. Place slices with grain of onion without cutting through completely, approx. 1/8 inch wide (strips should still be attached to the root)
5. Place 3 horizontal slices halfway up the onion without cutting through completely
6. Slice onion against grain approx. 1/8 inch cuts to stem
7. When the onion gets too thin to slice again, tip onion onto the face of the last cut. Proceed to place slices until you get to the stem
8. Chop the remaining onion that’s adjacent to the stem
9. Enjoy and feel superior to your friends

Paste

Onion past is used when you want zero structural integrity with your cooking. While this can be achieved with a blender or even a food processor, where is the fun in that? We are here to learn how to prep our onions with our hands and a knife, no fancy machines. Uses include smooth sauces, spreads, and foods requiring a very specific texture.

1. Remove stem of onion
2. Slice onion in half through root
3. Remove skin of onion
4. Place slices with grain of onion without cutting through completely as thin as possible (strips should still be attached to the root)
5. Place 3 horizontal slices halfway up the onion without cutting through completely
6. Slice onion against grain as thin as possible
7. When the onion gets too thin to slice again, tip onion onto the face of the last cut. Proceed to place slices until you get to the stem
8. Chop the remaining onion that’s adjacent to the stem
9. Press the flat of your knife against the onion and drag across your cutting board to pulverize the onion into a paste
10. Continue till all onion is in a paste
11. Enjoy 

Bonus, Fancy AF Dice

Oh, you’re an overachiever and want to be even fancier? I got you.

Have you ever wanted your onions to be up to a Micheline star level? This is the chop for you.

In this method, we separate the individual layers of the onion to achieve a perfectly uniform cut. If performed correctly the finished product will be a perfect cube. The previously explained way of fine dicing an onion works well for the vast majority of people and applications and if this is you, this is not necessary. However, if you are dropping the money on some fancy seafood or wagyu or you’re trying to impress the in-law’s, you should know how to achieve this level of quality.  Uses include garnishes, sauces, salads, salsas, chimichurri, and sandwiches.

1. Remove stem of onion
2. Slice onion in half through root
3. Remove root of onion halves
4. Remove skin of onion
5. Separate individual layers of the onion
6. Place cut with grain the same thickness as the layer of onion
7. Slice against the grain of the Julienne strips the same thickness
8. Repeat on all layers of the onion
9. Enjoy your onion perfection 

Please enjoy and keep cooking!