Sauce from the heart of Czechoslovakia's capital (4)
I believe the answer is:
ragu
'sauce' is the definition.
(I've seen this before)
'the heart of czechoslovakia's capital' is the wordplay.
'the heart of' indicates the central letters.
'czechoslovakia's capital' becomes 'prague'.
The middle letters of 'prague' are 'RAGU'.
'from' acts as a link.
(Other definitions for ragu that I've seen before include "tomato and meat sauce" , "pasta sauce" .)