Ingredient in his pudding (4)
I believe the answer is:
spud
'ingredient' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'in his pudding?' is the wordplay.
'in' says the answer is hidden in the clue.
'SPUD' can be found hidden inside 'his pudding'.
Can you help me to learn more?
(Other definitions for spud that I've seen before include "Vegetable" , "One could be in jacket" , "Tattie" , "Potato (informal)" , "Murphy" .)