Snack bar's offering primarily beans and pork sausages (4)
I believe the answer is:
baps
'snack bar's offering' is the definition.
(a snack bar might sell baps)
'primarily beans and pork sausages' is the wordplay.
'primarily' suggests taking the first letters.
The first letters of 'beans and pork sausages' is 'BAPS'.
(Other definitions for baps that I've seen before include "buns" , "Round rolls of soft bread" .)