Cook wants right means of keeping fish fresh? (4)
I believe the answer is:
gill
'fresh?' is the definition.
(thesaurus)
'cook wants right' is the wordplay.
'cook' becomes 'grill' (grilling is a form of cooking).
'wants' indicates named letters should be taken away ('want' can mean 'lack').
'right' becomes 'r' (abbreviation).
'grill' with 'r' taken away is 'GILL'.
'means of keeping fish' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for gill that I've seen before include "Respiratory organ of fish" , "A little drink" , "Fish's breathing apparatus" , "Organ for breathing under water" , "Small liquid measure" .)