When I dry shiitakes I cut out the stem; dried they are too tough. But there is a lot of flavor in them for soups. It’s easier to cut the stems into small pieces fresh then pop them into a bag in the freezer, or vacuum seal if you have a lot. The same principle works for the bottom portion of asparagus; I trim any dried or tough bottoms and freeze them for later. One later is this soup.
Variations: