Han zi heok aka Sweet Potato Leaves

Still no kangkong but saw sweet potato leaves. How come those in sg are purple in colour? Anyways, I didn't realize that the stems are, erm, kinda woody. Next time, I'll just use the leaves. :P Fry the hae bee hiam and wah lau...the whole house smells leh! Tsk....tsk.....
I like it but the stems are really CMI (cannot make it)! :(