Who provides food three queens perhaps wanted? (7)
I believe the answer is:
caterer
'who provides food' is the definition.
(caterers supply food)
'three queens perhaps wanted?' is the wordplay.
I cannot really understand how this works, but
'three' could be 'ter' (see Chambers) and 'ter' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for caterer that I've seen before include "Provider of refreshments" , "Provider of food and drink" , "Provider of food/drink" , "Refreshment supplier" , "Someone needed for party" .)