Cooked pure supply of food that’s kosher (9)
I believe the answer is:
reputable
'kosher' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
'cooked pure supply of food' is the wordplay.
'cooked' is an anagram indicator.
'supply of food' becomes 'table' (I can't explain this - if you can you should give a lot more credence to this answer).
'pure' is an anagram of 'repu'.
'repu'+'table'='REPUTABLE'
'that's' is the link.
Can you help me to learn more?
(Other definitions for reputable that I've seen before include "Trustworthy" , "Well thought of" , "of good name" , "Respected" , "Upright" .)