One poaching beef in recipe with awful result (7)
I believe the answer is:
rustler
'one poaching beef' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'recipe with awful result' is the wordplay.
'recipe' becomes 'r' (abbreviation in medical prescriptions).
'with' is a charade indicator (letters next to each other).
'awful' indicates an anagram.
'result' with letters rearranged gives 'ustler'.
'r'+'ustler'='RUSTLER'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for rustler that I've seen before include "Horse thief" , "Cattle-robber" , "Stock taker?" , "Cattle stealer" , "Livestock thief" .)