Choy gon (菜乾) is dried or dehydrated bok choy. Often bok choy is dried under the sun. Besides, people like to use choy gon to make congee and soup. In Chinese medicine practice, choy gon helps with cold, coughing, moisturizing lungs and remove internal heat (熱氣). However, it's not suitable for people who have weak spleen. Also, choy gon needs to be washed and soaked into water in order to remove dirt and bugs.