Bad character, but he can cook (7)
I believe the answer is:
poacher
'bad character but he' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'cook' is the wordplay.
I cannot really see how this works, but
'cook' could be 'poach' (poaching is a kind of cooking) and 'poach' is located in the answer.
The remaining letters 'er' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'can' acts as a link.
Can you help me to learn more?
(Other definitions for poacher that I've seen before include "Stealer of game" , "Gamekeeper's foe" , "He sometimes turns gamekeeper" , "Pilferer" , "Illegal game hunter" .)