In a small saucepan, combine the condensed soup (do not add water) and cornstarch and simmer over medium heat until thick, 2 to 3 minutes.
Let cool until warm to the touch. Pour onto a drying sheet set in a dehydrator tray to make one leather and dehydrate at 155°F (68°C) for 8 to 10 hours. After 4 hours, when the top of the soup is dry, it is important to flip the drying sheet over onto the dehydrating tray and peel the drying sheet away. Because of the higher temperature used to dehydrate this, case hardening can occur and this will help prevent that from happening, allowing the soup to dry all the way through. When dehydrated, it should be dry and brittle, and break or crumble easily.
If you vacuum seal with an oxygen absorber, it will keep up to 1 month in the pantry, 6 months in the refrigerator, or 1 year in the freezer. If kept in a ziptop plastic freezer bag, it will keep in the refrigerator for 1 month and be good for 5 days once removed from the refrigerator if kept cool and dry.
Pour 2 cups boiling water over the leather, cover, and let stand for 10 minutes. Stir and enjoy.
