Combine the rest of the ingredients (except wonton wrappers in a food processor and pulse to combine - you just want small pieces not a puree.
Spoon a tablespoon of filling into each wrapper and use a finger to dab some water around the edges. Fold wrappers over filling and pinch to seal shut. If you are not going to cook immediately, place dumplings on parchment, under a nice damp towel and refrigerate until ready (I'd say up to 24 hours, anything more and you should freeze them - see note if so).
Place dumplings in parchment-lined bamboo steamer with enough space between them so that they are not touching.
Steam dumplings over simmering water for 10-12 minutes.*
*If you do not have a bamboo steamer (and/or you want to pan fry your dumplings) you can heat up oil in a large skillet, once the dumplings have browned on the bottom pour enough water into the pan to cover dumplings about ¼ inch - careful it will splatter - cover and cook 10-12 minutes.
Notes
These freeze nicely and can be pulled out for a quick and easy snack or dinner. Freeze once dumplings are filled, before you steam them. To cook simply pull out of the freezer and place into steamer - they may take an extra minute to cook but not much longer. They will keep for 3-4 months.
Recipe by Eat Some Wear Some at https://eatsomewearsome.com/miso-mushroom-dumplings/