Dish made small in homage to Penny (5)
I believe the answer is:
'dish' is the definition.
(type of meal or dish)
'small in homage to penny' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'in homage' becomes 'ala' (I am not sure about this - if you are sure you should believe this answer much more).
'to penny' becomes 'd' (abbreviation e.g. Lsd - pounds, shillings, pence).
'made' acts as a link.
Can you help me to learn more?
(Other definitions for salad that I've seen before include "Cold dish of raw vegetables" , "Raw greens, mainly" , "Cold dish of vegetables or fruits" , "A dish of lettuce and vegetables" , "one gets dressed" .)