Done, a Milanese dish? (5)
I believe the answer is:
pasta
'milanese dish?' is the definition.
(pasta might be eaten in Milan)
'done a' is the wordplay.
'done' becomes 'past' (both can mean finished).
'past'+'a'='PASTA'
(Other definitions for pasta that I've seen before include "Processed flour dough" , "Macaroni, for example" , "Spaghetti, perhaps" , "The stuff of spaghetti, macaroni etc" , "dish high in carbohydrates" .)