To make elderberry juice from dried elderberries, simmer 1 cup of dried berries with 2 cups of water on low heat on the stove for 30 minutes, then blend in blender. Strain out all debris through cheesecloth.
On low heat, mix together all ingredients and simmer for 10 minutes. Add more masa if you want a thicker sauce.
Use immediately or store in glass jar in the refrigerator for up to 2 weeks.