Cook in oven after second in fridge (5)
I believe the answer is:
roast
'cook' is the definition.
(roasting is a kind of cooking)
'oven after second in fridge' is the wordplay.
'oven' becomes 'oast' (type of kiln).
'after' says to put letters next to each other.
'second in fridge' becomes 'r' (2nd letter of 'fridge').
'oast' put after 'r' is 'ROAST'.
'in' acts as a link.
(Other definitions for roast that I've seen before include "Have a go at" , "Cook, eg, joint of meat" , "Heavily criticise" , "Sunday dinner" , "The Sunday -----, with all the trimmings!" .)