The vegetables that are grown in the largest quantities around the world are the tomato and the potato. But the most widely used vegetable is the onion.
The onion appears in more dishes and in more countries than any other vegetable. In some places, the onion is used to flavor dishes, while in other countries it’s eaten by itself as a vegetable.
The ancient Egyptians ate onions both ways, for the onion was the most common vegetable in Egypt 5,000 years ago. During the Middle Ages, the onion and a relative of the onion, the leek, were the only common vegetables in Europe.
Today, more than 20 billion pounds of onions are produced around the world each year.
Emperor Nero of Rome ate leeks because he thought they would improve his singing voice.