Rush away to dine, tucking into simple, delicious morsel? (4,1,7)
I believe the answer is:
beat a retreat
'rush away' is the definition.
(to beat a retreat is to run away)
'dine tucking into simple delicious morsel?' is the wordplay.
'dine' becomes 'eat' (eat a meal).
'tucking into' is an insertion indicator.
'simple' becomes 'bare' (synonyms).
'delicious morsel?' becomes 'treat'.
'eat' inserted within 'bare' is 'beatare'.
'beatare'+'treat'='BEAT A RETREAT'
'to' is the link.
(Other definitions for beat a retreat that I've seen before include "Retire hastily" , "Withdraw quickly" , "Go away in a hurry" , "Depart hastily" , "Withdraw to avoid something unpleasant" .)