Number outside a church for food (5)
I believe the answer is:
nacho
'food' is the definition.
(nacho is a kind of food)
'number outside a church' is the wordplay.
'number' becomes 'no' (abbreviation for 'number').
'outside' means one lot of letters goes inside another.
'church' becomes 'ch' (common abbreviation).
'a'+'ch'='ach'
'no' placed around 'ach' is 'NACHO'.
'for' acts as a link.
(Other definitions for nacho that I've seen before include "Mexican food item" , "chip production line unit" , "Mexican snack item" , "Tortilla chip topped with cheese and spices" , "kind of chip" .)