Crossword Genius

Begin small quiche (5)

Ross

I believe the answer is:

'begin' is the definition.
(synonyms)

'small quiche' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'quiche' becomes 'tart'.
's'+'tart'='START'

(Other definitions for start that I've seen before include "Origin", "Move quickly < when surprised", "open", "launch", "Beginning".)

I've seen this clue in Mirror.