Heather meets head of institute in college for food (8)
I believe the answer is:
linguini
'food' is the definition.
(linguini is a kind of food)
'heather meets head of institute in college' is the wordplay.
'heather' becomes 'ling' ('ling' can be a synonym of 'heather').
'meets' is a charade indicator (letters next to each other).
'head of' suggests taking the first letters.
'in' is an insertion indicator.
'college' becomes 'uni' (I've seen this in other clues**).
The initial letter of 'institute' is 'i'.
'i' inserted into 'uni' is 'uini'.
'ling'+'uini'='LINGUINI'
'for' is the link.
(Other definitions for linguini that I've seen before include "Ribbonlike pasta" , "Flat, thin pasta" , "dish in Milan?" , "Long thin pasta" , "food" .)