Weed or vegetable?

Recently we noticed a new vegetable dish on the menu of a coffee-shop-restaurant that we frequent. The name is "田七菜" (Tián qī cài where the literal translation is as follows: 田 = paddy field, 七 = seven, 菜 = vegetable) and we ordered it to see what sort of vegetable it is.

A google search revealed that it is known as Madeira Vine or Mignonette Vine or Anredera cordifolia. Many countries considered it as a weed and pest as it grows easily and can kill other plants and trees that it grows on. However its bulbil is used as a herb in Chinese Medicine for tonifying kidney, removing stasis and dispersing swelling according to the Medicinal Plant Images Database created by the School of Chinese Medicine and the Hong Kong Baptist University Library.

Stirfried 田七菜 - the taste is slightly bitter and the leaves are thick with a smooth slippery texture (mucilaginous texture) similar to the texture of Malabar Spinach (帝王苗 - Dìwáng miáo).

Fleshy heart-shaped leaf