Developing Culinary Knife Skills: How to Dice an Onion

There are a few basic skills that are necessities in the kitchen. If you’re a home cook in training, you’ll have to master these or always be faced with stumbling blocks when you cook. Don’t get too intimidated, though; many of these culinary steps have to do with cutting, dicing, or chopping staple ingredients. And if you’re a Knife Depot fan, it’s probably safe to assume you know a bit about knives. This means it shouldn’t take too much to make sure you’re comfortable putting away your Bowie knife and sharpening your kitchen knives.

To help you in this learning process, we reached out to Kathy Maister, the woman behind StartCooking.com. Her website is a wonderful guide for learning the basics of cooking and picking up some easy, tasty recipes. We asked Ms. Maister about one of the most basic skills: dicing onions. Diced onions are a regular part of recipes, but many people are unsure how to tackle the root veggie. Here are Ms. Maister’s tips on choosing the right knife for the job, dicing onions, and cleaning up after the job.

Choosing your knife

There are three knives Ms. Maister couldn’t live without: a chef’s knife, a serrated knife, and a paring knife. That said, she also recommends you dice the onion using whatever knife with which you feel the most comfortable. If you’re choosing from her trio of knives, the chef’s knife has the length and strength needed to help you get through a big onion. So as long as you aren’t worried to use the big knife, it’s a great choice!

Cut off the stem end

Take a look at your onion. There are obviously two ends: the root and the stem. To identify which is which, look for the stringy roots hanging out of the skin; that’s the root end. The stem end protrudes and is usually covered in skin. Cut about half an inch off the stem end.

Cut the onion in half

Stand the onion upright on its now-flat end. Cut it vertically in half from the root to the bottom.

Peel the onion

The uncertainty of how to hold an onion while cutting is what makes onion dicing a daunting task for so many people. On her website, Ms. Maister shares a really easy trick for using the onion’s skin as a holder. It changes the way you peel the onion, so read the steps first. However, if you don’t share in the conundrum of how to hold an onion, go ahead and peel it. With the cuts you have made, the skin should peel off easily. Frequently, the top layer of the onion will also come off – this is fine.

Make slices towards the root

Point the knife blade towards the root end and make vertical slices to within ½” of the root. Ms. Maister uses ¼” spaces between cuts for chopped onions as a size guideline. Since diced is the middle ground between chopped and minced, make your cuts only slightly less spaced out than ¼”.

Make horizontal slices

If you used Ms. Maister’s trick for making a holder out of the skin (like we did), this is when you’ll be holding it. Otherwise, hold the onion by the root end and make sure you keep your knuckles in to avoid nicking yourself with the knife. Now, cut parallel to the root, slicing all the way through the onion. Keep your slices spread out the same distance as you did in the last step.

Repeat and voila!

Repeat these steps with the other onion half. Because of the natural rings, you now have easily diced onions!

Washing your knives

Ms. Maister recommends that you wash your knives by hand. Use a soapy sponge and always keep the blade pointed away from you.