This is something I probably should have figured out for myself ages ago, but I didn’t really learn it until I took this class at Charleston Cooks. It is very easy and will minimize the time you need to spend cutting the onion, which should reduce onion-y tears as well.
First, peel the top layer off the onion and rinse the onion off. Then cut it in half from the root to the tip.
Cut the non-hairy ends off and turn one of the halves over so the flat side is on the cutting board.
And what do you know? The magic onion fairy left cutting guides for you. Wasn’t that nice?
Slice the onion in narrow rows, roughly following the lines. The root side is helpful here because it helps keep the whole thing together. Then turn the onion and cut straight down, keeping your rows about the same as when you had guides.
Discard the root end. Repeat with the other half of the onion.
Now wash your hands. We’re trying to avoid onion-y tears, after all.