I dry all my backpacking foods at home and have done the butternut squash soup leather thing for years. Here's my current procedure---
**Cook up a big pot of organic brown rice.
** Once cooked put into blender.
** Add butternut squash soup into blender with rice such as---
** Blend thoroughly using added water to allow blender to work well.
** Pour mix onto silicone dryer sheets and home dry and later ziplock.
By blending up the cooked rice you can rehydrate in the field quickly with no cooking and only bringing water to a boil to add to the mix and putting in pot cozy for 30 minutes.
You can do this blended brown rice trick with soups, tomato soups, vegetarian chilis like Amy's canned stuff, broccoli soups, etc.
Here is some dried sweet potato soup ready for the ziplock. Break it up and place it in your cook pot with water and bring to a boil and place in pot cozy for 30 minutes. Voila, you got soup.