Middle Eastern serial about head of intelligence (7)
I believe the answer is:
israeli
'middle eastern' is the definition.
(I've seen this before)
'serial about head of intelligence' is the wordplay.
'about' indicates an anagram.
'head of' suggests taking the first letters.
The initial letter of 'intelligence' is 'i'.
'serial' with letters rearranged gives 'israel'.
'israel'+'i'='ISRAELI'
(Other definitions for israeli that I've seen before include "Faithful inhabitant" , "from Mediterranean country" , "From Jaffa, say?" , "Jew in a state" , "Relating to a Mediterranean nation" .)