Dish Dinah and Alec prepared (9)
I believe the answer is:
enchilada
'dish' is the definition.
(enchilada is a kind of dish)
'dinah and alec prepared' is the wordplay.
'and' says to put letters next to each other (I've seen this in other clues).
'prepared' indicates anagramming the letters.
'dinah' after 'alec' is 'alecdinah'.
'alecdinah' with letters rearranged gives 'ENCHILADA'.
(Other definitions for enchilada that I've seen before include "spicy food" , "Mexican food" , "spicy titbit" , "spicy snack" , "Filled tortilla served with chilli sauce" .)