Fruit and a lot of cereal in a jar (7)
I believe the answer is:
apricot
'fruit' is the definition.
(type of fruit)
'a lot of cereal in a jar' is the wordplay.
'lot of' means to remove the last letter (a lot of the word but not all of it).
'cereal' becomes 'rice' (rice is a kind of cereal).
'in' means one lot of letters goes inside another.
'a jar' becomes 'pot' (I've seen this in other clues).
'rice' with its last letter taken off is 'ric'.
'ric' inserted into 'pot' is 'pricot'.
'a'+'pricot'='APRICOT'
'and' acts as a link.
(Other definitions for apricot that I've seen before include "Rip coat (anag) - fruit" , "Fruit resembling a peach" , "shade" , "Small, peach-like fruit" , "A fruit-tree" .)