How to chop an onion

For some of you this will seem like we’re trying to teach you to suck eggs, (which incidentally, you do by placing the egg in your mouth) but for those of you that don’t have much kitchen experience each issue will include a how to guide for some of the basics you’ll need to know...

The first stage is to prepare the onion. Chop off both ends with a sharp knife then slice along the middle from end to end. It is now much easier to peel. Remove the brown outer skin (and possibly the next layer if it seems damaged or looks too green.

Now holding one half with the fl at edge on the chopping board make several horizontal cuts about halfway into the onion. You can then chop down creating small slices using the natural layers to reduce the number of cuts necessary. To finish, simply repeat the action from the other end.

The final stage is generally to cry your eyes out. This is because enzymes that were separate now mix with sulfenic acids in the onion to produce propanethiol S-oxide, a volatile sulphur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulphuric acid. The sulphuric acid burns, stimulating your eyes to release more tears to wash the irritant away. One way to help reduce this is to keep the onion refrigerated before cutting it. Or ‘borrow’ some safety goggles from a chemistry student.