Pan collection is about to commit murder (7)
I believe the answer is:
skillet
'pan' is the definition.
(I know that skillet is a type of pan)
'collection is about to commit murder' is the wordplay.
'collection' becomes 'set' (set is a kind of collection).
'is about' means one lot of letters goes inside another.
'to commit murder' becomes 'kill' (I can't explain this - if you can you should believe this answer much more).
'set' enclosing 'kill' is 'SKILLET'.
Can you help me to learn more?
(Other definitions for skillet that I've seen before include "Frying-pan" , "Cooking-pot" , "Small long-handled pan" , "Metal cooking pot with long handle" , "Long-handled cooking pot" .)