Welsh dish arbiter cracked (7)
I believe the answer is:
rarebit
'welsh dish' is the definition.
(I've seen this in another clue)
'arbiter cracked' is the wordplay.
'cracked' indicates anagramming the letters.
'arbiter' with letters rearranged gives 'RAREBIT'.
(Other definitions for rarebit that I've seen before include "Simple dish" , "which the Welsh take down?" , "Toasted cheese and bread" , "Arbiter of traditional Welsh dish" , "mouthful?" .)