Approximating dried mushroom texture without For yet another variation on using dried/fresh mushrooms, I would like to know how to approximate the texture of dried mushrooms using fresh.

My intent is to make a leek-miso soup and I would like to add dried shiitake for their texture (flavor too, sure, but it is already a flavorful soup). Unfortunately, the market near me only has fresh mushrooms (portabella, baby bella, snow cap, and other normals). But alas, I also do not have a food dehydrator.

How can I manipulate the mushrooms to approximate the same chewy texture? My thought is that long, slow baking at a very low temp would dry them out. Is this intuition right? Should I prep the mushrooms before hand in anyway?
I have accidentally gotten that texture by putting leftover stir-fried sliced shitake in the fridge uncovered. Leather.