Dashing to provide service with seafood (7)
I believe the answer is:
raffish
'dashing' is the definition.
('raffish' can be a synonym of 'dashing')
'service with seafood' is the wordplay.
'service' becomes 'raf'.
'with' means one lot of letters go next to another.
'seafood' becomes 'fish' (fish is a kind of seafood**).
'raf'+'fish'='RAFFISH'
'to provide' is the link.
(Other definitions for raffish that I've seen before include "like British airmen?" , "Tawdry" , "Rakish" , "Vulgarly flashy, disreputable" , "Carelessly dressed" .)