Fragment of artichoke heart on roll (7)
I believe the answer is:
crumble
'fragment' is the definition.
(I've seen this before)
'artichoke heart on roll' is the wordplay.
'heart' means to look at the middle letters.
'on' says to put letters next to each other.
'roll' becomes 'rumble'.
The middle letter of 'artichoke' is 'c'.
'c'+'rumble'='CRUMBLE'
'of' is the link.
(Other definitions for crumble that I've seen before include "Fall to bits; a pudding" , "Fall to pieces - dessert" , "(To) fragment; pudding" , "Break into small fragments" , "Type of pudding - disintegrate" .)