Slice of Urda wrapped in red fish (5)
I believe the answer is:
trout
'fish' is the definition.
(I know that trout is a type of fish)
'slice of urda wrapped in red' is the wordplay.
I cannot really understand how this works, but
'of' could be 'o' and 'o' is found within the answer.
'red' could be 'r' (I've seen this in other clues) and 'r' is found within the answer.
The remaining letters 'tut' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for trout that I've seen before include "Commonly caught fish" , "Swimmer" , "Food fish" , "Mistiness" , "tickled to death?" .)