Cut sweet potato into halves and bake in the oven for 50 minutes.
Finely chop the onion and green chilli. Grate the ginger. Roughly chop the kale, removing the thick stalks.
Remove the sweet potatoes from the oven and let cool for 10 minutes. Add the cooked sweet potato, the coconut milk and nutritional yeast to a Vitamix or any kind of food blender and blend until completely smooth
In a large pot, saute the onions in coconut oil (or water) until translucent and add the onion and green chilli along with the grated ginger. Saute for a couple of minutes. Add the mixture from the blender to the pot along with two cups of veggie stock, and turn the heat up to an almost boil. Season with salt and pepper and the cayenne (or paprika). Turn heat to low and add the kale leaves.
Simmer on low for a few minutes.
Serve in bowls with crusty sourdough bread. Top the soup with sprigs of fresh coriander.