Tucking into junk, devour cooked dish (4,7)
I believe the answer is:
hors doeuvre
'dish' is the definition.
(I have seen 'Appetizing dish' mean 'hors doeuvre' so perhaps 'dish' could also mean 'hors doeuvre')
'tucking into junk devour cooked' is the wordplay.
'tucking into' means one lot of letters goes inside another.
'junk' becomes 'horse' (synonyms).
'cooked' is an anagram indicator (letters cooked into a new form).
'devour' anagrammed gives 'doeuvr'.
'horse' going around 'doeuvr' is 'HORS DOEUVRE'.
(Other definitions for hors doeuvre that I've seen before include "Savoury appetising dish" , "Canape" , "Appetiser" , "Starter course" , "Savoury appetizer" .)