Quickly consuming eastern banquet (5)
I believe the answer is:
feast
'banquet' is the definition.
(I know that banquet can be written as feast)
'quickly consuming eastern' is the wordplay.
'quickly' becomes 'fast' (synonyms).
'consuming' indicates putting letters inside.
'eastern' becomes 'e'.
'fast' going around 'e' is 'FEAST'.
(Other definitions for feast that I've seen before include "Huge nosh-up" , "Lavish spread" , "Celebratory meal" , "Repast" , "wine and dine" .)