This is a mysterious green leaf vegetable, I've attempted a couple of searches for a common name but there does not appear to be a consensus. Australia's Department of Primary Industries lists at least 27 names for this tender leaf vine, designating the name Ceylon Spinach for locals. This leafy green is commonly found in Asian markets, and occasionally on menus of Asian restaurants. Under what name? I have no idea. If you have one or a couple, let me know. I'm sure the Australian government would love to know as well.
How was it? I think it is like what spinach hybridized with okra would taste like, tender and a bit slimy, but delicious - if you like okra. I liked it, and will cook it again.