Heat the coconut oil in a large pot. Add the onion and garlic and saute until translucent, about 5 minutes.
Add the diced apple, curry powder, chili pepper and ginger. Saute for a further 5 minutes.
Meanwhile, peel and dice the sweet potatoes. Transfer them to the pot, along with the lentils, vegetable stock and coconut milk. Season with salt and pepper. Put the lid on the pot and simmer for 20 minutes.
Using an immersion blender (or a food processor), blend to your desired consistency. Garnish with chopped cilantro (coriander) and lime wedges.