Instrument produced by gypsy chap cutting steak (8)
I believe the answer is:
trombone
'instrument' is the definition.
(trombone is a kind of instrument)
'gypsy chap cutting steak' is the wordplay.
'gypsy chap' becomes 'rom' (member of the Romani people).
'cutting' means one lot of letters goes inside another (some letters cut their way into a word).
'steak' becomes 'tbone' (T-bone steak is an example).
'rom' placed inside 'tbone' is 'TROMBONE'.
'produced by' acts as a link.
(Other definitions for trombone that I've seen before include "Brass band instrument" , "source of notes" , "Brass instrument with sliding tubes" , "Musical instrument with long slide" , "Bfrass wind instrument with slide" .)