Basics: How to chop an onion without tears

All the acids which cause your eyes to water are concentrated in the root end of the onion so the way to avoid tears is to avoid the root end of the onion.

Using a strong sharp knife, cut off the stalk end of the onion.

Peel back all the outer layers of the onion, if possible keep the outer layers intact as they make a convenient handle. 

Slice lengthways through the onion but don't go right down to the root, repeat this across the onion,


then turn it around other way and slice through again to produce a criss cross pattern  pictured below

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Lay the onion on its side and slice across the the diameter of the onion and as the pieces fall off you will see that they are diced.




If you want slices  rather than diced onion, stop when you have the criss cross pattern and just cut the root end off.

Now just toss the root end and the outer layers in the bin and you are done - onions chopped and dry eyes in the house.