I agree with the above: just an Eb#9,#11
Never consciously heard it played or played it myself with the m7 on top, unless it's the melody, but anyone would know what the chord is if it's supposed to be an Eb7 of some kind. I'd just as soon stick the #11 on top, or the third or the raised nine.
I personally don't use the slash chord notation when writing lead sheets, but IME a lot of bassists do speak in those terms, and arguably a lot of reharmonizations of pop tunes come from them, so it's good to at least know a few ways to write a chord symbol.
You can probably find that chord in "Goodbye Porkpie Hat," somewhere.