To make this delicious recipe, start by heating a large, heavy-bottomed soup pot over medium heat. Once the pot is hot, add the coconut oil and let it melt. Then, add the onions and stir. Sauté the onions until they become translucent and soft, stirring occasionally, for about 5 minutes. Next, add pepper flakes, coriander, cumin, and turmeric to the pot and sauté until fragrant, about 1 minute. Then, add the ginger and garlic to the pot and cook for another minute. Finally, season the pot with a pinch of salt and pepper.
Gently add the sweet potatoes to the pot and stir them around to ensure they are evenly coated in the spices. Next, incorporate the lentils into the pot and give everything a good stir. Generously season with salt and pepper. Pour the vegetable stock into the pot, stirring until all the browned bits on the bottom of the pot have been scraped up. Place the lid on top of the pot, then bring the contents to a boil.
Bring the stew to a boil, reduce the heat to a simmer and leave the lid slightly ajar. This allows the steam to escape. Let it simmer for around 30 minutes, or until the sweet potatoes are soft and begin to fall apart, and the lentils are tender. The liquid should also reduce by about one-third.
To complete your hearty winter soup with sweet potato, add the coconut milk and kale to the pot and stir. Place the lid on top and let the stew simmer until the kale is wilted and a vibrant green, which should take around 3-4 minutes. To bring out the flavors, season the stew with a dash of salt and pepper. Reheat the stew up to a strong simmer and then taste it to check the seasoning. You may need to adjust the amount of spices to get the desired flavor or heat level. Make sure to write down any adjustments you make to the recipe so that you can replicate the same flavor in the future.
Serve the soup with sweet potato and coconut milk hot with chopped cilantro, extra pepper flakes, lime wedges, and a sprinkling of toasted pumpkin seeds.