Sweet Potato Soup with Cassava and Plantain

• 1 ¾ pounds sweet potato
• 2 onions, grated
• 2 tbsp. s

Peel the sweet potatoes and cut into chunks. Sauté the sweet potatoes along with the onions in a large pan with the sunflower oil. Add 4 cups of the vegetable stock and cook for about 30 minutes, until the sweet potatoes are tender. Transfer to a blender along with the remaining 2 cups vegetable stock and puree until the soup is smooth or use an immersion blender. Finally, add the sour cream an