cook · side · american

How to Dice an Onion

Name: How to Dice an Onion
Cuisine: american

Cut off both ends, halve the onion through the root, peel away the papery skin, then make horizontal cuts followed by vertical cuts to create uniform dice. Keep the root end intact until the final cuts to hold everything together.

Total time: 3 min
Hands-on: 3 min
Serves: 1 medium onion
Difficulty: Easy

Before you start

Sharp knife, stable board

A dull knife will crush the onion cells and make you cry more. Use a cutting board that won't slip.

chef's knife
cutting board

Ingredients

1 medium yellow onion

The guiding cuts

Root end stays intact

Leave about a quarter-inch of the root end uncut until the very end. This holds the onion layers together so your dice stays neat instead of falling apart.

Step by step

Trim the ends. Cut off the stem end completely. Trim the root end but leave about a quarter-inch of the base intact.
Halve and peel. Stand the onion on the cut stem end. Slice straight down through the root to create two halves. Peel away the papery outer skin and the first layer if it feels slimy.
Make horizontal cuts. Place one half cut-side down. Hold it steady with your fingers curled under. Make 2-3 horizontal cuts parallel to the board, stopping just short of the root end.
Make vertical cuts. Turn your knife perpendicular and make vertical cuts from stem to root, spacing them according to your desired dice size. Again, stop just short of the root.
Dice across. Finally, cut across the vertical cuts to create dice. The onion will naturally separate into uniform pieces as you work toward the root end.

Tips & troubleshooting

Chill the onion for 30 minutes before cutting to reduce tears
Keep your knife blade against your knuckles as a guide and move your fingers back as you cut
Save the root ends and peels in the freezer for vegetable stock

Variations

Fine dice. Make cuts about 1/8-inch apart for brunoise or to disappear into sauces
Rough chop. Skip the horizontal cuts entirely and just make wider vertical cuts followed by rough crosscuts
Sliced onions. Cut the halves into crescents by slicing from root to stem in curved lines

Questions

Why does my diced onion fall apart?: You're cutting through the root end too early. That base holds everything together until the final cuts.
How do I get more even pieces?: Focus on consistent spacing in your cuts rather than speed. Each cut should be roughly the same distance from the last.
Can I dice onions ahead of time?: Yes, but store them covered in the refrigerator and use within a day. They'll start to smell strong and lose their bite.