 Luckily, a colleague of mine recently spoke to a few experts to see what onion cutting tricks are actually worth the salt. Number one, try chilling the onion before you cut it in the fridge, freezer, or a bowl of ice water just for a couple of minutes. Or microwave it for 30 seconds or so as long as you're using it for something that doesn't require it to stay crispy. Number two, if you won't mess up the flavor of what you're cooking, squeeze a lemon on the onion before you cut it.