Church has genuine breakfast (6)
I believe the answer is:
cereal
'breakfast' is the definition.
(I've seen this before)
'church has genuine' is the wordplay.
'church' becomes 'CE' (Church of England).
'has' means one lot of letters go next to another.
'genuine' becomes 'real' (associated in meaning).
'ce'+'real'='CEREAL'
(Other definitions for cereal that I've seen before include "Breakfast food made from grain" , "Starchy grains used as food" , "Eg, wheat, rye, corn" , "Contents of breakfast bowl" , "output from harvest?" .)