Traveller cutting steak produces an instrument (8)
I believe the answer is:
trombone
'an instrument' is the definition.
(trombone is a kind of instrument)
'traveller cutting steak' is the wordplay.
'traveller' becomes 'rom' (individual belonging to the Romani people).
'cutting' is an insertion indicator (some letters cut their way into a word).
'steak' becomes 'tbone' (T-bone steak is an example).
'rom' placed within 'tbone' is 'TROMBONE'.
'produces' is the link.
(Other definitions for trombone that I've seen before include "Brass musical instrument with slide" , "Bfrass wind instrument with slide" , "play this" , "Blow me!" , "Brass instrument with sliding tubes" .)