Whether you’re dicing, slicing or chopping, knowing how to cut an onion is an essential skill to start many dishes. From cozy dinner ideas (hello, french onion soup!) to easy appetizers and delicious vegetable side dishes (roasted balsamic onions, anyone?), onions are the base of so many delicious recipes (and bonus: they’re also good for you!). Learning how to peel and chop an onion well sets you up for cooking success. Plus, with these Good Housekeeping Test Kitchen-approved tips and techniques, you’ll be done with this task quickly, meaning even those choppers who cry while cutting onions may avoid the tears — but more on that later.
Our top tip when cutting onions? Invest in the best knife and keep it sharp. This ensures easier, more even cuts and fewer chances for the knife to slip around. Keep your fingers away from the blade and tucked under your knuckles; this is sometimes called a bear grip and it protects your digits from danger.
But even if you don’t have the sharpest knife in the theoretical shed, you can still follow the tips below as long as you take extra care to protect your fingers when chopping (dull blades are more prone to slips). Read on to learn our go-to methods for how to cut an onion, including how to slice, dice and mince an onion.
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How to cut onions without crying
There are plenty of tricks out there that suggest everything from wearing goggles (this trick makes the most sense; contact lens wearers also experience less onion-related tears) to holding a match between your teeth. Our fail-proof solution is to use an ultra-sharp knife and work quickly, which helps to keep the compounds in onions that make you cry intact in the vegetable. If you need a refresher on how to sharpen a knife, look no further!
How to peel an onion
Peeling an onion is typically step one of any onion preparation. Remove the stem ends by slicing through, then place the flat end on your cutting board and slice through the root end lengthwise. Then starting at the exposed end of the onion tear away the outer layers of skin exposing the flesh of the onion. Now you’re ready to slice, dice or mince!
FYI: When you’re prepping to dice an onion, it’s easier if you don’t cut off the bottom and tops of the onion. It’ll result in a mess of onion petals that are impossible to dice uniformly. If you’re slicing, however, you can slice off both the root end and the stem end.
How to slice an onion
1. Once your onion is peeled, place onion, cut side down firmly on your cutting board.
2. Starting at the stem end, slice perpendicularly all the way through the onion, creating half moons. Be sure to pay attention to the thickness of slice your recipe requires (some recipes benefit from super thin slices, while others want thicker pieces).
How to dice an onion
1. Lay the onion flat against the cutting board, cut side down. Cut the onion horizontally with a knife parallel to the cutting board toward the root end, but not cutting all the way through.
2. Then, cut vertically down through the onion, still leaving the root end intact.
3. Finally, rotate the onion so the root end is toward your non-cutting hand, and slice across, holding the root end in your hand.
How to mince an onion
Mincing an onion is simply turning a diced onion into finer pieces, great for starting dishes like creamy risotto.
Once your onion is diced, place the pointed end of your chef’s knife on your cutting board, with your non-dominate hand on top, and rock the handle back and forth, moving throughout the diced onion, and continue until the desired size of onion is achieved.
Once your onions are cut, it is best to use right away, but you can store in the fridge in an airtight container for up to 4 days.
Becca Miller (she/her) has been working in the Good Housekeeping Test Kitchen since 2018, where she researches and writes about tasty recipes, food trends and top cooking tools. She graduated from NYU with a liberal arts degree focusing on creative writing. She makes killer scrambled eggs, enjoys a glass of un-oaked chardonnay and takes pride in her love of reality television.