Jews ears Auricularia auricula-judae are an interesting one. Firstly they have (reputed) medicinal qualities, suck them for sore throats not to mention cancer fighting properties. And the name is intriguing too. It could be because in the middle ages the Jews suffered very bad persecution in Europe and could only find mushrooms to eat or because Judas reputedly hung himself on an Elder tree. Personally I think it unlikely Judas would have picked an Elder tree to hang himself on, but hey we all have our favourite hanging trees I guess, and I have seen references to all fungi being historically known as Jew meat.
Pick them and dry them out, powder in a pestle & mortar and you have a stew thickening agent. Lots of flavour in very fresh large ones.