Strike in the canteen? (6)
I believe the answer is:
buffet
This clue is a double definition.
'strike' is the first definition.
(I know that buffet is a type of strike)
'the canteen?' is the second definition.
(thesaurus)
'in' acts as a link.
(Other definitions for buffet that I've seen before include "Self-service meal - pound" , "self-service place" , "Kind of meal where guests serve themselves (6)" , "Meal at which people help themselves" , "Help yourself table" .)