Each in the vessel producing a hymn of praise (5)
I believe the answer is:
paean
'a hymn of praise' is the definition.
(song of praise)
'each in the vessel' is the wordplay.
'each' becomes 'ea' (abbreviation).
'in the' means one lot of letters goes inside another.
'vessel' becomes 'pan' (vessel or container for cooking).
'ea' going inside 'pan' is 'PAEAN'.
'producing' acts as a link.
(Other definitions for paean that I've seen before include "Hymn of praise" , "work building up" , "Triumphal song" , "Anthem" , "Formal expression of praise" .)