Where man might eat dog’s breakfast? (4)

I believe the answer is:
mess
'dog's breakfast?' is the definition.
(I've seen this before)
'where man might eat' is the wordplay.
I cannot quite see how this works, but
'man' could be 'm' (M is an abbreviation for male or masculine) and 'm' is located in the answer.
The remaining letters 'ess' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for mess that I've seen before include "Confused person" , "terrible state" , "State of confusion or untidiness" , "Eating place" , "difficulty" .)
