Cooked with cheese (2,6)
I believe the answer is:
au gratin
'cooked with cheese' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for au gratin that I've seen before include "Cooked with browned melted cheese" , "baked with a coating of breadcrumbs" , "Cooked, covered with breadcrumbs" , "Crumby" , "Cooked covered with cheese" .)