Heat the oil or butter in a large saucepan over medium heat.
Add the onion and cook until just tender, about 5 minutes.
Stir in the carrots, sweet potatoes, garlic, sage and nutmeg along with a generous pinch of salt and pepper and cook for 10-15 minutes until vegetables have broken down and softened slightly.
Add in the vegetable broth and bring to a simmer, then reduce heat to medium low and cook until vegetables have completely softened, another 10 minutes. Remove 1 cup vegetables with broth and puree in a blender (or use an immersion blender) then add back to the pan.
Just before serving, stir in kale until just wilted then remove from heat and stir in coconut milk and lime juice. Season to taste with salt/fresh black pepper and serve.