My favorite mushroom! Have never seen them already sliced, though.
Did you see this earlier thread?
The miso butter would work really nicely on them – saute them first, then finish with the compound butter.
The way I most often make them, though, is yakitori-style (but on a fry pan). Tare sauce here but you can use commercial teriyaki or oyster / stir-fry sauce. Pictured here and here.
