Recently, I found myself with quite a few onions in my kitchen. I was afraid of them going bad before I could use them, so I chopped them all up to store in the freezer. Yes, all six of them and not a single tear was shed.
There are two sides to the onion: the root
and the top of the onion that grew out of the ground.
It is important to use a sharp knife for chopping an onion. A dull knife will slip and is dangerous to your fingers. So with a sharp knife, slice about a half inch off the top. Make sure you are slicing the top of the onion and not the root side. The root will keep the onion intact as you are chopping.
Now slice the onion in half down the middle of the root.
With your fingers, peel off the papery top layer. You might need to peel off the entire first layer of the onion too depending on its quality.
You now have two halves of an onion that are ready to be chopped.
As shown in the picture below, starting at the root end, make long slices. I use the ridges of the onion to guide my slices. Do not cut all the way through the root; remember the root keeps the onion intact for chopping.
Holding on to the root side, start slicing off the onion width wise. Chop all the way to the root.
You have now chopped an onion.
I place each chopped onion in an individual freezer container. When I have a recipe that calls for an onion, I can just pull a container out in the morning to thaw in the refrigerator.