Food must be so from area covered by European list (7)
I believe the answer is:
eatable
'food must be so' is the definition.
(food must be edible or eatable)
'area covered by european list' is the wordplay.
'area' becomes 'a' (maths abbreviation).
'covered by' means one lot of letters go next to another (on top of in a down clue).
'european' becomes 'E' (abbreviation e.g. EU).
'list' becomes 'table' (I've seen this in other clues).
'a' put after 'e' is 'ea'.
'ea'+'table'='EATABLE'
'from' acts as a link.
(Other definitions for eatable that I've seen before include "Fit for food" , "Fit for consumption" , "Digestible" , "Comestible" , "Edible" .)