If you fake roux with half arrow, half pulverized mushrooms, you really egt the mojo. This is the only use I have for powder from the giant puffball.

Still, I purchased shiitakes and maitakes from dollar stores, further dehydrate them and pulverize in a processor or spice grinder and use to thicken tomato sauces, gravies, and other things that just need a little bit of glue to hold them together.

Hen of the Woods is an ideal thickener. Must be VERY dry to pulverize, though. They can get tough and will test your processor. Puff balls are the easist to turn to powder. Not the quality of a "hen" or boletes, but decent.