Miroton mushroom

Slices of mushroom cooked with onions, and various ingredients which may vary. It's an easy recipe with very little preparation.
Sometimes it is writen mironton in french, but it seems to be by confusion.
The mironton is old slang from a suspicious individual in the mob. The word appears in an old folk song ("Malbrough s'en va-t-en guerre") where it does not seem to have well-defined meaning.