Country where one is raised tucking into fish (7)
I believe the answer is:
tunisia
'country' is the definition.
(Tunisia is an example)
'one is raised tucking into fish' is the wordplay.
'one' becomes 'i' (Roman numeral).
'raised' says the letters should be written in reverse.
'tucking into' means one lot of letters goes inside another.
'fish' becomes 'tuna' (tuna fish is a kind of fish**).
'is' reversed gives 'si'.
'i'+'si'='isi'
'isi' going into 'tuna' is 'TUNISIA'.
'where' is the link.
(Other definitions for tunisia that I've seen before include "Country in North Africa" , "African republic on the Mediterranean coast" , "N African country in which ancient Carthage lies" , "As Inuit visits there in North Africa" , "Republic in northwestern Africa" .)