The origin: China
Thousand-year-old eggs make a special dish in most parts of China. They make it by covering the raw duck eggs in a special mixture made of ash, clay, straw, quicklime and salt. The eggs are left to stay for some weeks or months and allowed to cure. The yolk of these eggs picks up a deep-green color and gets a soft texture. The white degenerates and turns to a transparent jelly like substance. These eggs are served with pork or silken tofu, ginger and scallions. Along with rice porridge, they are known as congee. Sometimes, they are also served a part of cold finger foods.