With most things in everyday life, the ManMade argument goes: if your going to do something, you might as well do it right. And while the definition of "right" is variable, oftentimes, we look to the pros. I take care of my vehicle the way a mechanic would, I work on my garden and lawn with the tips I learned from farmers, and I try to prep and cook food in the same way as those who doing for a living.
I can't remember when I first learned to dice an onion (probably from all those years of absorbing PBS cooking shows), but there's an easy way to make quick (and safe) work of breaking one down into evenly sized pieces. Primer offers this "30 second visual guide" and it does a great job of walking you through this classic method.
I'm sure there's some French word that describes the technique (if you know it, share in the comments below, please) but for now we'll just call it the most effective way to dice and onion.
Check out Primer's guide in full - How to Dice an Onion Like a Chef: A 30 Second Visual Guide