Set of instructions for preparing a dish (6)
I believe the answer is:
recipe
'set of instructions for preparing a dish' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for recipe that I've seen before include "Directions for food preparation" , "Set of instructions for preparing a dish" , "Formula for making something" , "Directions for cooking a dish" , "Cookery instructions" .)