Dip bagel in starchy food (4)
I believe the answer is:
sago
'starchy food' is the definition.
(I've seen this in another clue)
'dip bagel' is the wordplay.
'dip' becomes 'sag' (I've seen this in another clue).
'bagel' becomes 'O' (circular).
'sag'+'o'='SAGO'
'in' is the link.
(Other definitions for sago that I've seen before include "Starchy food as white pudding" , "Cereal, used in pudding" , "Starchy pudding cereal" , "Palm cereal" , "Starchy cereal used in puddings" .)