Nick the crackers in chef's domain (7)
I believe the answer is:
kitchen
'chef's domain' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'nick the crackers' is the wordplay.
'crackers' indicates an anagram (informal term for mad).
'nick'+'the'='nickthe'
'nickthe' is an anagram of 'KITCHEN'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for kitchen that I've seen before include "Area for preparing meals" , "Room for food" , "Cooking area" , "Site of 4 [GAS OVEN]" , "where food is a concern" .)