Gentleman taken aback by German dish (7)
I believe the answer is:
risotto
'dish' is the definition.
(risotto is a kind of dish)
'gentleman taken aback by german' is the wordplay.
'gentleman' becomes 'sir' (I've seen this before).
'taken aback' says the letters should be written backwards.
'by' is a charade indicator (letters next to each other).
'german' becomes 'otto' (I've seen this before**).
'sir' back-to-front is 'ris'.
'ris'+'otto'='RISOTTO'
(Other definitions for risotto that I've seen before include "Italian course" , "You cook it in stock" , "Italian dish cooked with broth" , "scoff" , "Savoury rice dish" .)