Soy egg

A soy egg is a type of egg in Chinese, Vietnamese, Japanese, Korean, and Mauritian cuisine which is boiled, peeled, and then cooked in a mixture of soy sauce, sugar, water, and other optional herbs and spices. Other ingredients such as meat, vegetables and tofu can be cooked in the same red cooking method, resulting in dishes generally referred to as lou mei. Soy eggs can be made from chicken, duck, and quail eggs. This preparation is very similar to that of tea eggs. A soy egg that has been repeatedly stewed and dried until dark and chewy is called iron egg. The Chinese soy sauce egg is called Lujidan or Ludan (滷蛋/卤蛋)it is one of the most popular type of street foods. The marinating sauce is called lushui (滷水/卤水)

Source: Wikipedia