A nut roast cooked for a high flier (9)
I believe the answer is:
astronaut
'a high flier' is the definition.
(I've seen this before)
'a nut roast cooked' is the wordplay.
'cooked' indicates an anagram (letters cooked into a new form).
'nut'+'roast'='nutroast'
'nutroast' with letters rearranged gives 'stronaut'.
'a'+'stronaut'='ASTRONAUT'
'for' acts as a link.
(Other definitions for astronaut that I've seen before include "High-flyer" , "spaceman" , "Buzz Aldrin, e.g." , "One travelling in space" , "High-flier" .)