Tea drinking was common in China for about one thousand years before anyone in Europe had ever heard about tea. People in Britain were much slower in finding out what tea was like, mainly because tea was very expensive. It could not be bought in shops and even those people who could afford to have it sent from Holland did so only because it was a fashionable curiosity. Some of them were not sure how to use it. They thought it was a vegetable and tried cooking the leaves. Then they served them mixed with butter and salt. They soon discovered their mistake but many people used to spread the used tea leaves on bread and give them to their children as sandwiches.