Tricky chip is to a green (9)
I believe the answer is:
pistachio
'green' is the definition.
(I have seen 'light green' mean 'pistachio' so perhaps 'green' could also mean 'pistachio')
'tricky chip is to a' is the wordplay.
'tricky' is an anagram indicator.
'chip'+'is'+'to'+'a'='chipistoa'
'chipistoa' with letters rearranged gives 'PISTACHIO'.
(Other definitions for pistachio that I've seen before include "nuts" , "Yellowish-green" , "nut-bearing tree" , "light green" , "Nut tree" .)