Cut an Onion in Five Steps
Onions hold together by their layers and by the root. Keep the root on until the last cut and the layers stay put while you work, which is why this method gives you even pieces. Below is the dice, then slices, wedges, and strips, then how to keep the tears down.
Fast Answer
Trim the stem end, halve the onion through the root, and peel it. Leave the root on, lay a half flat, make a few horizontal cuts, then vertical cuts toward the root, then slice across. You get even dice that cook at the same speed.
Start Here
- This is for you if: your onion pieces come out uneven, or the onion slides around while you cut.
- When to use this: any time a recipe says chopped, diced, or minced onion.
- Success looks like: even pieces that cook at the same speed, with only the root left over.
Step-by-Step: How to Dice an Onion
- 1. Trim the stem end. Cut off the pointed top. Leave the hairy root end on.
- 2. Halve through the root. Cut from top to root so each half keeps part of the root. Peel off the skin.
- 3. Lay a half flat. Cut side down. Curl your fingertips under your guiding hand and keep your knuckles against the flat of the blade.
- 4. Make horizontal cuts. Slice parallel to the board toward the root, but don't cut through it. Use 1 cut for a small onion, 2 to 3 for a large one.
- 5. Make vertical cuts. Cut from top to root, spaced the width of the dice you want. Don't cut through the root.
- 6. Slice across. Cut crosswise and the dice fall away. Discard the root end when you're done.
Onion Dice Sizes
- Small dice, about ¼ inch: sautés, soups, and sauces where the onion melts into the dish.
- Medium dice, about ½ inch: the all-purpose size for most cooking.
- Large dice, about ¾ inch: when you want the onion to hold its shape, like stews and roasting.
Small Dice
About 1/4-inch pieces. Best for sautés, soups, and sauces where onions should melt into the dish.
Medium Dice
About 1/2-inch pieces. A versatile size that works for most everyday cooking.
Large Dice
About 3/4-inch pieces. Best when you want the onion to hold its shape and texture.
How to Cut an Onion Without Crying
- Use a sharp knife. It's the best-supported tip. A sharp blade slices cleanly and breaks fewer cells, so less of the irritating gas is released.
- Work quickly and keep the cut side down. It limits how much gas reaches your face.
- Chill the onion first. 15 to 30 minutes in the refrigerator may help a little. The evidence is limited, so don't count on it.
- Add ventilation. A fan or vent hood blowing away from you helps move the gas off.
- Take a break. If your eyes are burning, step away rather than rubbing them.
Which Cut for Which Dish
- Diced: soups, sauces, salsa, stuffing. See the steps above.
- Half-moon slices: burgers, sandwiches, caramelized onions, and salads.
- Strips: fajitas and stir-fries.
- Wedges: roasting and grilling.
- Rings: onion rings and grilling.
- Chopped or minced: see the box below.
How to Slice an Onion (Half-Moons)
- 1. Trim and halve. Cut off the stem end and halve through the root. Peel.
- 2. Lay a half flat. Cut side down, root to one side. Curl your fingertips under.
- 3. Slice across. Cut crosswise, from stem end to root, at the thickness you want. About ¼ inch works for burgers and sandwiches.
- 4. Thicker for caramelizing. Cut about ⅜ inch so the slices don't melt away.
How to Cut an Onion Into Strips
- 1. Trim and halve. Cut off the stem end, halve through the root, and peel.
- 2. Lay a half flat. Cut side down.
- 3. Slice from stem to root. Follow the lines of the layers, about ¼ to ½ inch apart. Stop at the root.
- 4. Trim the root. Cut off the root and discard it. The strips hold their shape in a hot pan, which makes them good for fajitas.
How to Cut an Onion Into Wedges
- 1. Trim the stem end only. Leave the root on and peel.
- 2. Halve through the root. Lay each half flat.
- 3. Cut each half into 2 to 4 wedges. Cut from the stem end down through the root. Each wedge keeps a bit of root, which holds the layers together.
- 4. Use right away. Wedges are good for roasting, grilling, and stews.
How to Cut Onion Rings
- 1. Trim both ends. Take off a thin slice from the stem end and the root end. Peel.
- 2. Stand the onion on a flat end. Hold it steady.
- 3. Slice crosswise. About ¼ to ½ inch thick, depending on the use.
- 4. Push the rings apart. Use the large outer rings for frying or grilling, and save the small center pieces for another use.
Chop vs. Mince vs. Dice
- Dice: even, uniform pieces, from ¼ to ¾ inch. Use the root-on method above.
- Chop: rougher and less even, about ½ to ¾ inch. A recipe that says "chopped onion" doesn't need perfect pieces. A dice works.
- Mince: very fine, smaller than ¼ inch. Make the small dice, then rock the knife back and forth over the pieces until they're fine.
Wasting Too Much Onion?
- Trim the root thinly. You only need enough root to hold the layers together. A thin slice at the end is enough.
- Trim the stem end lightly too. Take off just the dry tip.
- Save the scraps. Ends and skins go in the freezer for stock.
- Other methods exist. Cutting vertically toward the center and then slicing across also works and wastes a bit less. The root-on method is just the easiest to control.
What Most Cooks Get Wrong
What Most Cooks Get Wrong
- Cutting off the root first. The onion falls apart and slides.
- Skipping the horizontal cuts. You get long strips, not dice.
- Using a dull knife. It crushes the onion, makes more tears, and slips.
- Cutting through the root. The layers separate before the last cut.
- Rushing. Uneven pieces burn while others stay raw.
Other Ways to Dice an Onion
- Rocking dice: fast, less even. Good for a fine dice when speed matters.
- Slice, then dice: beginner-friendly, but pieces vary more.
- Food processor: quick for bulk. Pulse so you don't end up with mush.
- Onion chopper tool: even pieces with little skill, but more cleanup.
Bottom line: use the root-on method for most cooking.
Frequently Asked Questions About Cutting an Onion
What is the best way to cut an onion? Trim the stem, halve it through the root, peel, make horizontal then vertical cuts toward the root, then slice across. Keeping the root on holds the layers together.
How do you cut an onion without crying? Use a sharp knife, work quickly, and ventilate. Chilling the onion first may help a little, but the evidence is limited.
How do you cut an onion into strips? Halve it through the root, peel, then slice from stem to root along the layers.
How do you cut an onion into wedges? Leave the root on and cut through it into 4 to 8 wedges. The root holds each wedge together.
How do you slice an onion for burgers? Slice it crosswise into rings, about ¼ inch thick, then separate the rings.
How do you cut an onion quickly? Use the root-on dice. Once you’ve practiced, it takes about a minute.
Should I leave the root on when cutting an onion? Yes, until the last cut. It holds the layers together, so the onion doesn’t slide. Trim it thin to waste less.
How big is a small, medium, and large dice? About ¼ inch, ½ inch, and ¾ inch.
3 Responses
Great teaching tool learned how to do it the right way ..thank you
Very wasteful! A huge portion of the root end is thrown away, as well as a rather large end of the blossom part.
Better to just cut minimally on the root and blossom, peel it, and then just do vertical cuts angled toward the center axis longitudinally, then slice transversely. The onion’s layers themselves will separate and the result is consistently sized pieces with minimal waste.
But Chef Mohr’s method is taught as gospel in the culinary schools, and Gabriel’s horn must blow before they’d consider a change from “the right way”.
Nice demonstration! To the “comment “ re: waste. So what, onions are cheap and plentiful. Dicing properly utilized maximum usage anyway. Further more, I thought he efficiently diced the demonstrated half anyway!