Pottery strike's working (6)
I believe the answer is:
Here is my best explanation:
'pottery' is the definition.
(Minton was a famous pottery manufacturer)
'strike's working' is the subsidiary indication.
'strike' becomes 'mint' ('mint' can be a synonym of 'strike').
'working' becomes 'on'.
(Other definitions for minton that I've seen before include "Pottery firm", "Stoke china", "ceramicist" and "English pottery company".)