Vietnamese Herb "Kim That Tai"

Are you familiar with a vietnamese herb called "kim that tai"? I want to cultivate this herb. I understand that this leafy herb is good for your blood. Some Vietnamese put it in their salad or just eat the leaves.

I am not familiar with this herb. On a Vietnamese discussion list this herb was identified as a species of Gynura, either G. aurantiaca or G. sarmentosa (https://www.datviet.com/forums/archive/index.php/t-46936.html). The english name is "velvet plant". It is a member of the daisy family growing 60-90 cm (2-3') tall with velvety leaves covered in soft purple hairs. The flowers are orange. There is a picture and more information at Cal's Plant of the Week website (https://www.plantoftheweek.org/week130.shtml).
The plant is sold as an ornamental pot plant in the West, so you may be able to find it at specialty nurseries.
I cannot vouch for the accuracy of the identification of the plant, nor for the safety of it as an edible plant.