Seven ingredients put in simmered -- he added ginger? (7)
I believe the answer is:
redhead
'ginger?' is the definition.
(both can mean someone with red hair)
'seven ingredients put in simmered he added' is the wordplay.
'seven ingredients put in' indicates a hidden word (seven letters from the clue).
'REDHEAD' is hidden within 'simmered he added'.
(Other definitions for redhead that I've seen before include "Person with distinctive coloured hair" , "Blue Australian" , "Ginger-haired person" , "Auburn type" , "Ginger nut?" .)