Chap entertaining longing for somewhere to cook (7)
I believe the answer is:
kitchen
'somewhere to cook' is the definition.
(room you cook food in)
'chap entertaining longing' is the wordplay.
'chap' becomes 'ken' (man's name).
'entertaining' is an insertion indicator.
'longing' becomes 'itch' (I've seen this before).
'ken' enclosing 'itch' is 'KITCHEN'.
'for' is the link.
(Other definitions for kitchen that I've seen before include "where food is a concern" , "Where heat's to be stood" , "Site of 4 [GAS OVEN]" , "food preparation area" , "Room - thicken (anag)" .)