What poi is made from (4)
I believe the answer is:
taro
'what poi is made from' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for taro that I've seen before include "Fortune-telling cards" , "Shortly pack" , "Starchy plant" , "Tropical plant with edible tuberous roots" , "A rot turns the lily-like plant" .)