Up-and-coming knight, German fellow, is a dish! (7)
I believe the answer is:
risotto
'dish' is the definition.
(risotto is a kind of dish)
'up-and-coming knight german fellow' is the wordplay.
'up-and-coming' says the letters should be written in reverse.
'knight' becomes 'sir' (I've seen this before).
'german fellow' becomes 'otto' (common German name).
'sir' written backwards gives 'ris'.
'ris'+'otto'='RISOTTO'
'is a' is the link.
(Other definitions for risotto that I've seen before include "Italian recipe" , "Perhaps Italian" , "dishy thing!" , "It has roots in Italian rice-based dish" , "Italian dish of rice, meat and vegetables" .)