Chap informally cooking tubers (6)
I believe the answer is:
buster
'chap informally' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe there's an association between them I don't understand?
'cooking tubers' is the wordplay.
'cooking' is an anagram indicator (letters cooked up into a new form).
'tubers' with letters rearranged gives 'BUSTER'.
Can you help me to learn more?
(Other definitions for buster that I've seen before include "- - Keaton, silent star" , "-- Keaton, comic actor" , "-- Keaton, US silent film actor" , "Keaton or Crabbe" , "Form of address to man" .)