Cooked in vapour (7)
I believe the answer is:
steamed
'cooked in vapour' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for steamed that I've seen before include "Proceeded with course" , "got really hot" , "Cooked over hot water" , "Cooked in vapour" , "Cooked over boiling water" .)