Country recipe with a so-called fish (6)
I believe the answer is:
rwanda
'country' is the definition.
(I know that Rwanda is a country)
'recipe with a so-called fish' is the wordplay.
'recipe' becomes 'r' (abbreviation in medical prescriptions).
'with' is a charade indicator (letters next to each other).
'a so-called fish' becomes 'Wanda' (as in the film A Fish Called Wanda).
'r'+'wanda'='RWANDA'
(Other definitions for rwanda that I've seen before include "Hutu and Tutsi country" , "Republic in central Africa" , "Kigali's country" , "Central African country" , "Language" .)