Catch fish illegally to cook in milk? (5)
I believe the answer is:
poach
'cook in milk?' is the definition.
'poach' can be an answer for 'cook' (thesaurus). I'm not certain of the 'in milk?' bit.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for poach that I've seen before include "Cook in boiling liquid - steal game" , "Appropriate" , "Steal (game etc)" , "Cook (an egg) in water" , "Take game illegally from land or water" .)