Nut cooking chips at Vigo regularly (9)
I believe the answer is:
pistachio
'nut' is the definition.
(I know that pistachio is a type of edible nut)
'cooking chips at vigo regularly' is the wordplay.
'cooking' is an anagram indicator (letters cooked up into a new form).
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'vigo' are 'io'.
'chips'+'at'='chipsat'
'chipsat' is an anagram of 'pistach'.
'pistach'+'io'='PISTACHIO'
(Other definitions for pistachio that I've seen before include "Green nut" , "light green" , "Edible pale green seed" , "Greenish nut" , "Food" .)