Unadulterated eastern food product (5)
I believe the answer is:
puree
'food product' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'unadulterated eastern' is the wordplay.
'unadulterated' becomes 'pure' (similar in meaning).
'eastern' becomes 'e'.
'pure'+'e'='PUREE'
Can you help me to learn more?
(Other definitions for puree that I've seen before include "food for babies?" , "Produce of blender" , "Pulped vegetable or fruit" , "Smooth pulped food" , "Pulped fruit or vegetables" .)