His stuff is nourishing, but expensive in France (7)
I believe the answer is:
butcher
'his stuff is nourishing' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'but expensive in france' is the wordplay.
'expensive in france' becomes 'cher' (I am not sure about this - if you are sure you should believe this answer much more).
'but'+'cher'='BUTCHER'
Can you help me to learn more?
(Other definitions for butcher that I've seen before include "Meat-seller" , "Slaughter" , "Killer" , "Purveyor of meats" , "Meat purveyor" .)