Behind on investment according to auditor delivering cut (4,5)
I believe the answer is:
rump steak
'cut' is the definition.
(I know that rump steak is a type of cut of beef)
'behind on investment according to auditor' is the wordplay.
I cannot quite understand how this works, but
'behind' could be 'rump' (informal term for the buttocks) and 'rump' is found in the answer.
The remaining letters 'steak' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'delivering' acts as a link.
Can you help me to learn more?
(Other definitions for rump steak that I've seen before include "Meat" , "Cut of beef" , "might be something for the barbecue" .)