Cereal brought in like nuts (6)
I believe the answer is:
acorns
'nuts' is the definition.
(I've seen this in another clue)
'cereal brought in like' is the wordplay.
'cereal' becomes 'corn' (corn is a kind of cereal).
'brought in' indicates putting letters inside.
'like' becomes 'as'.
'corn' placed within 'as' is 'ACORNS'.
(Other definitions for acorns that I've seen before include "Potential oaks?" , "'From little . . . . . . mighty oaks do grow'" , "'Great oaks from little ...... grow'" , "From which 23 down grow" , "wild fruit" .)