Some bread sandwiches dry before I interfere (4,2)
I believe the answer is:
butt in
'interfere' is the definition.
(I've seen this in another clue)
'some bread sandwiches dry before i' is the wordplay.
'some bread' becomes 'bun' (bun is a kind of bread).
'sandwiches' is an insertion indicator (goes on either side like a sandwich).
'dry' becomes 'tt' (abbreviation for teetotal).
'before' means one lot of letters go next to another.
'tt'+'i'='tti'
'bun' enclosing 'tti' is 'BUTT IN'.
(Other definitions for butt in that I've seen before include "Give unwanted twopenceworth, perhaps" , "Break into a conversation" , "Interrupt or meddle - head first?" , "Interrupt a conversation" , "Interrupt or meddle - like goat?" .)