Cook uses Aga to make a bite to eat (7)
I believe the answer is:
sausage
'a bite to eat' is the definition.
(sausage is a type of food)
'cook uses aga' is the wordplay.
'cook' indicates anagramming the letters.
'uses'+'aga'='usesaga'
'usesaga' is an anagram of 'SAUSAGE'.
'to make' is the link.
(Other definitions for sausage that I've seen before include "Tasty tube of meat" , "that should be edible" , "Tube-shaped food item" , "Eg, salami or cervelat" , "Long, bagged meat product" .)