Very quick sauce is about right (6)
I believe the answer is:
presto
'very quick' is the definition.
'sauce is about right' is the wordplay.
'sauce' becomes 'pesto' (pesto is a type of sauce).
'is about' indicates putting letters inside.
'right' becomes 'r' (common abbreviation).
'pesto' enclosing 'r' is 'PRESTO'.
(Other definitions for presto that I've seen before include "In quick tempo (mus.)" , "at great speed..." , "Moving quickly" , "Poster (anag.)" , "29 [ADAGIO]? On the contrary" .)