Having dried some mushrooms to a crisp for storage...
... I got to wondering what I might do with them in this state, apart from rehydrating and adding to stews and suchlike. As a first step, I tried powdering them, potentially for using as stock. It turns out that a pestle and mortar makes short work of this job. I haven't yet tried it, but I imagine I could make a pretty good smooth mushroom sauce from this powder.
Today, I had another idea. I had an open tub of mascarpone cheese in the fridge, which I'm quite partial to at the best of times. I took a large dollop of that and mixed it with my powdered mushrooms - about half and half cep and chanterelle - and, um, that was it. It took quite a bit of mixing, and the result is a fairly firm paté, as the dried mushrooms absorb moisture from the cheese.
Wow, this is sublime! Of course, the crucial part is finding the right mushrooms in the first place (and note that this is only suitable for mushrooms that can be eaten raw), but once they've got as far as the storage jar, this is a very easy treat. I'm counting this one as a success.