Fill endless menu with Cheddar, say (7)
I believe the answer is:
engorge
'fill' is the definition.
(thesaurus)
'endless menu with cheddar say' is the wordplay.
'endless' means to look at the middle letters.
'with' is a charade indicator (letters next to each other).
'cheddar say' becomes 'gorge' (Cheddar Gorge is a gorge in Somerset).
The central letters of 'menu' are 'en'.
'en'+'gorge'='ENGORGE'
(Other definitions for engorge that I've seen before include "Congest with blood - eat greedily" , "Eat immodestly" , "Eat ravenously" , "Cause to swell with fluid" , "Swell with blood, water, etc" .)