Spanish bread, once prepared, coated with seeds (7)
I believe the answer is:
pesetas
'spanish bread' is the definition.
(I've seen this in another clue)
'prepared coated with seeds' is the wordplay.
'prepared' becomes 'set' (set up or ready).
'coated with' indicates putting letters inside.
'seeds' becomes 'peas' (I have seen 'Edible seeds ' mean 'peas' so perhaps 'seeds' could also mean 'peas').
'set' inserted into 'peas' is 'PESETAS'.
'once' is the link.
(Other definitions for pesetas that I've seen before include "Old Spanish money" , "Units of Spanish money" , "Spanish bread no longer used" , "Former currency of Spain" , "Old units of Spanish currency before euros" .)