Rioja to start is excessive with nothing but a rice dish (7)
I believe the answer is:
risotto
'a rice dish' is the definition.
(I've seen this before)
'rioja to start is excessive with nothing' is the wordplay.
'to start' says to take the initial letters.
'excessive' becomes 'ott' (short for 'over the top' - informal British).
'with nothing' becomes 'o' (I've seen this in other clues).
The initial letter of 'rioja' is 'r'.
'r'+'is'+'ott'+'o'='RISOTTO'
'but' is the link.
(Other definitions for risotto that I've seen before include "Perhaps Italian" , "dishy thing!" , "Italian recipe" , "Italian course" , "F" .)