Break the cinnamon stick. Crush the remaining dry spices in a mortar. Put the grated ginger with the cinnamon and the other spices in a saucepan and roast briefly until the spices start to smell. Pour in the water and simmer for about 6-8 minutes over a low flame. Then add the rooibos tea and let the tea steep for about 8-10 minutes over a low flame. Add the soy milk (milk) and strain the tea through a tea strainer into a pot. Sweeten with agave syrup or honey.
Annotation:
The specified amount of sweetener has been deliberately kept low. If you like it sweet, just take a little more agave syrup or honey.