Food enthusiast gobbles starter for lunch (4)
I believe the answer is:
flan
'food' is the definition.
(flan is a kind of food)
'enthusiast gobbles starter for lunch' is the wordplay.
'enthusiast' becomes 'fan' (fan is a kind of enthusiast).
'gobbles' means one lot of letters goes inside another.
'starter for' indicates taking the first letters.
The first letter of 'lunch' is 'l'.
'fan' enclosing 'l' is 'FLAN'.
(Other definitions for flan that I've seen before include "Sweet/savoury open tart" , "Open-topped pastry dish" , "Open pastry dish" , "Open-topped tart" , "Flat open tart" .)