American spies graduate teetotaller with a long Italian loaf (8)
I believe the answer is:
ciabatta
'long italian loaf' is the definition.
(type of Italian bread)
'american spies graduate teetotaller with a' is the wordplay.
'american spies' becomes 'cia' (Central Intelligence Agency).
'graduate' becomes 'ba'.
'teetotaller' becomes 'tt' (abbreviation).
'with' says to put letters next to each other.
'cia'+'ba'+'tt'+'a'='CIABATTA'
(Other definitions for ciabatta that I've seen before include "Variety of Italian bread" , "Flat Italian bread made with olive oil" , "Light flat Italian bread" , "Light Italian bread made with olive oil" , "Type of Italian bread" .)