A trotter possibly for cooking? (5)
I believe the answer is:
afoot
'cooking?' is the definition.
(both can mean in progress)
'a trotter possibly' is the wordplay.
'trotter possibly' becomes 'foot' (trotter is a kind of foot).
'a'+'foot'='AFOOT'
'for' is the link.
(Other definitions for afoot that I've seen before include "Currently in progress" , "In the wind" , "Going on" , "Happening" , "In the pipeline" .)