Onions are the backbone of thousands of savory dishes, from chili to marinara to salsa to soup. They’re also one-third of the holy trinity known as mirepoix (celery, carrots, and onions), which is used to add flavor and aroma to both restaurant and home-cooked meals. Given how often they appear in recipes, knowing how to chop an onion will make you a stronger cook right out of the gate.
But before you can begin chopping, it’s essential to know how to pick a good onion. Whether you’re working with white, yellow, red (sometimes called purple), sweet/Vidalia onions, or even shallots—a close cousin of the onion—start by picking firm, fully intact bulbs with tight skin, which indicates freshness (the more flaky and papery the skin, the longer it’s been hanging around).
Let's begin by learning the basics of cutting onions:
In general, a chop yields larger squares of onion, which are appropriate for soups and sautés in which you don’t mind seeing and tasting the onion. Dicing creates slightly smaller pieces than a chop (and is sometimes called a small chop). When in doubt, a dice will work in most recipes. And, finally, mincing renders the smallest pieces of onion —useful in fine cuisine, or anytime you want the onion to disappear into a dish. Mincing is also ideal for a salsa or pico de gallo in which the onion will be consumed raw.
When sliced, onions emit a compound that gets into the air and can irritate the nerves around the eyes, causing you to tear up. (Science types, you can refer to this as “syn-propanethial-S-oxide.”)
Knowing why onions make you cry doesn’t help you avoid it—but you have a few options here. Got a little time? Peel and wash the onions, then place them in resealable bags and allow them to chill in the freezer for 10-15 minutes. Chilling onions before slicing can slow down the chemical chain reaction, allowing you to finish chopping before the tears flow. Also, always be sure to chop an onion with a sharp knife; using a dull tool mashes rather than cuts the onion, releasing more of the tear-inducing compounds. Finally, use protective eyewear. If you wear contact lenses, you’re in luck, as they provide a good barrier to irritation. If you don’t, consider kitchen goggles (ski, swim, or safety goggles work too). Alas, regular glasses provide some protection, but not quite as much as the aforementioned options.
Now that you’re an old pro at chopping onions, put your skills to good use in these recipes: