Food for father's volunteers (5)
I believe the answer is:
pasta
'food' is the definition.
(pasta is a kind of food)
'father's volunteers' is the wordplay.
'father's' becomes 'pas' (pa is a kind of father).
'volunteers' becomes 'ta' (abbreviation for Territorial Army).
'pas'+'ta'='PASTA'
'for' is the link.
(Other definitions for pasta that I've seen before include "Eg, spaghetti" , "Staple Italian food base" , "Fusilli, penne etc" , "Dish of dough made with durum wheat" , "Dried flour paste, staple in Italian food" .)