Does pie get cooked in one instalment? (7)
I believe the answer is:
episode
'one instalment?' is the definition.
('episode' can be a synonym of 'instalment')
'does pie get cooked' is the wordplay.
'get cooked' indicates an anagram.
'does'+'pie'='doespie'
'doespie' anagrammed gives 'EPISODE'.
'in' acts as a link.
(Other definitions for episode that I've seen before include "Set of incidents" , "Distinctive incident" , "Chapter or event" , "Musical passage" , "Incident or event as part of sequence" .)