Cashmere ordered? I don't know the answer to that (6,2)
I believe the answer is:
search me
'i don't know the answer to that' is the definition.
'search me' can be an answer for 'i don't know' (I've seen this before). I am not sure about the remainder of the definition.
'cashmere ordered?' is the wordplay.
'ordered?' indicates an anagram.
'cashmere' is an anagram of 'SEARCH ME'.
Can you help me to learn more?
(Other definitions for search me that I've seen before include "Church reciting book" , "what customs officer might do" , "Examination set on this writer" , "Who knows? 14 [NOT-I] !" , "check my pockets" .)