Cooked mixture of milk and eggs (7)
I believe the answer is:
custard
'cooked mixture of milk and eggs' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for custard that I've seen before include "Sweet sauce made with milk and eggs" , "-- Pie; -- apple" , "Dessert sauce" , "Type of apple" , "Pudding sauce" .)