Type of dish — cereal's so different (9)
I believe the answer is:
casserole
'type of dish' is the definition.
'cereal's so different' is the wordplay.
'different' is an anagram indicator (letters placed in a different order).
'cereals'+'so'='cerealsso'
'cerealsso' with letters rearranged gives 'CASSEROLE'.
(Other definitions for casserole that I've seen before include "Make a stew" , "Kind of stew" , "(Food cooked in a) stewpot" , "Dish cooked in an earthenware pot" , "Cook slowly" .)