It is best to use a microwave to heat it, so that it will heat through quickly. If you don't have a microwave, you have to use an iron pan to heat it. When it's hot, add less boiling water. The vermicelli becomes thicker when it is cold, so it is best to add boiling water when it is hot. When hot, bring to a boil over high heat, then simmer over low heat for two minutes before serving. In this way, the hot pickled cabbage vermicelli is delicious and almost the same as freshly stewed.