Dish in sink blocking channel (7)
I believe the answer is:
lasagne
'dish' is the definition.
(lasagne is a kind of dish)
'sink blocking channel' is the wordplay.
'sink' becomes 'sag' (sagging is a kind of sinking).
'blocking' is an insertion indicator (block can mean to plug a gap in something).
'channel' becomes 'lane' (both can mean a pathway).
'sag' going into 'lane' is 'LASAGNE'.
'in' is the link.
(Other definitions for lasagne that I've seen before include "Sheet pasta" , "Eat this as angel" , "Flat sheets of pasta" , "Type of pasta" , "Tasty Italian dish with layers of mince in pasta" .)