(Hani Mohammed | The Associated Press) In this Oct. 1, 2018, photo, a man prepares Halas for his children, a climbing vine of green leaves, in Aslam, Hajjah, Yemen. The leaves are made into green paste and used to be a traditional side dish, but at times of extreme poverty, it becomes the main meal. The UN agencies are warning that at least 3.5 million others might slip into the pre-famine stage.