Cook needs the right oven (5)
I believe the answer is:
roast
'cook' is the definition.
(roasting is a kind of cooking)
'the right oven' is the wordplay.
'the right' becomes 'r' (common abbreviation).
'oven' becomes 'oast' (oast is a kind of oven).
'r'+'oast'='ROAST'
'needs' is the link.
(Other definitions for roast that I've seen before include "Give a telling off to - cook" , "Traditional Sunday lunch" , "Cook with dry heat" , "Become very warm" , "Reprimand - cook" .)