As jstar noted it is daun gedi or as we say in Manado daong gedi. It s indeed one of these veggie used in many different ways in the manadonese cuisine, the most well known being perhaps in the famous tinutuan, associated with bayam merah, sambiki (pumpkin), kangkong (kangkung in BI) and rice.
no idea what it is called in English though.
It grows very easily. We have a bunch of trees that we harvest regularly.