Manage to cook on occasion (4,2)
I believe the answer is:
make do
'manage' is the definition.
(I've seen this in another clue)
'cook on occasion' is the wordplay.
'cook' becomes 'make' (synonyms).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'occasion' becomes 'do' (do is a kind of occasion).
'make'+'do'='MAKE-DO'
'to' acts as a link.
(Other definitions for make do that I've seen before include "Strange thing" , "Manage with something unsatisfactory" , "attend function" , "Manage with something not fully satisfactory" , "not expect better facilities" .)