For example good cooking ingredient (3)
I believe the answer is:
egg
'cooking ingredient' is the definition.
The definition and answer can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'for example good' is the wordplay.
'for example' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'good' becomes 'g' (abbreviation).
'eg'+'g'='EGG'
Can you help me to learn more?
(Other definitions for egg that I've seen before include "Urge (someone on )" , "One beaten by a whisker perhaps" , "Item with a yolk" , "start in life" , "Item of food" .)