What's in hasty work using recycled materials (6)
I believe the answer is:
rehash
'work using recycled materials' is the definition.
I can't tell whether this defines the answer.
'what's in hasty' is the wordplay.
'what' becomes 'eh' (sound used to ask 'what?' or 'pardon?').
'in' means one lot of letters goes inside another.
'hasty' becomes 'rash' (I've seen this in another clue).
'eh' inserted inside 'rash' is 'REHASH'.
Can you help me to learn more?
(Other definitions for rehash that I've seen before include "Work over (used material)" , "Recycled material" , "Re-use old material with little or no change" , "Use again, with few or no changes" , "new disposition" .)