As far as we know the Sumerians in present day Iraq were the first to perfect the stone arch. Only one of these arches still stands today in the ancient city of Ur, estimated to be 4,500 years old.
Later on ancient Romans and Greeks perfected the design, still seen today in many aqueducts and this arch over the entrance tunnel to the first Olympic stadium build around 600 B.C.
All this was going through my head one day, as I was again pondering, while cutting onions, why we always strive to cut round vegetables into cubes. I have watched respected chefs dice an onion, and I was never happy with that technique. There was always side pieces of onion lost and it was hard to hold onto the pile of onion, once it had been sliced top to bottom and then again horizontally.
While trying to think of a more even dice of concentric circles, I came to the conclusion of cutting these layers in a radial pattern, which is not just more even, it is also much more stable. And here is where the ancient Sumerians and their stone arch comes in. When you put pressure on the stone arch (weight of the stones) or the onion, it actually holds together, as in gripping the onion with your finger tips and putting pressure on with your knife.
Long story short, it is easier and you get a more even dice.
The onion’s anti-cancer & anti-inflammatory properties have been more and more bred out in an attempt to make onions sweeter and sweeter, where some of the new sweet varieties have as much sugar as an apple. The best onions to stick with are the pungent ones, yes the tear jerkers and also shallots. As a general rule, fruits and vegetables that are closest to their wild relatives are always more potent in phytochemicals, which can help the body ward off disease. A plants phytochemicals are always greatest on the outer layers, where the plant uses these chemicals to fight insects, disease, unfavorable weather, etc. It is best to peel away as little of your onion as possible. You can always use the outer layers for soup or stock, if they are too rubbery or dry to use. In general pesticide residues on onions are fairly low, so you don’t have to feel pressured to find organic varieties.
If you are cutting an onion not as a flavoring, where dicing is preferred, but as part of your dish, think fajitas or grilled for a sandwich, you might want to cut your onions in strips, long ways.
To find out more about Phytochemicals check this out http://www.precisionnutrition.com/phytochemicals