Dish as ordered by boy (5)
I believe the answer is:
'dish' is the definition.
(type of meal or dish)
'as ordered by boy' is the wordplay.
'ordered' indicates anagramming the letters.
'by' is a charade indicator (letters next to each other).
'boy' becomes 'lad' (informal term for boy).
'as' anagrammed gives 'sa'.
(Other definitions for salad that I've seen before include "one gets dressed" , "Raw vegetables, etc" , "Lettuce, cucumber etc" , "Food dish" , "Raw greens, mainly" .)