Dish is found in cave, unopened (7)
I believe the answer is:
risotto
'dish' is the definition.
(risotto is a kind of dish)
'is found in cave unopened' is the wordplay.
'found in' means one lot of letters goes inside another.
'cave' becomes 'grotto' (grotto is a kind of cave).
'unopened' means to remove the first letter (the opening of the word is removed).
'grotto' with its first letter removed is 'rotto'.
'is' placed inside 'rotto' is 'RISOTTO'.
(Other definitions for risotto that I've seen before include "It has roots in Italian rice-based dish" , "Italian course" , "scoff" , "Italian food" , "Italian dish of rice, meat and vegetables" .)