Wing Yip and most Chinese Shops as well as some of the larger supermarkets stock Green Tea, which has great anti-oxidant properties as well as other benefits.

Temple of Heaven (Brand Name) Chinese Green Tea 250g packet at Wing Yip costs £1. I like to use the loose tea as it gives me control. A couple of grains is better than plain water.

You can also obtain Green Tea Teabags from there and other shops which work out dearer.

Take care.