Club ingredient (5)
I believe the answer is:
bacon
'club ingredient' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bacon that I've seen before include "Thin slices of smoked ham" , "Meat (that's brought home?)" , "Old scientist" , "Man killed by chicken, some say" , "Cured pig-meat" .)