Melt the coconut oil in a heavy bottomed stock pot over medium heat. Stir in the shallot and fry gently until it softens and releases its fragrance. Stir in the poblano pepper and fry until softened - about 4 minutes. Add the sweet potatoes to the pot along with cumin, paprika and sea salt. Cover the pot and sweat the potatoes until they soften, about 10 minutes. Pour in the chicken stock and simmer, covered, for 30 minutes or until the potatoes fall apart when pierced with a fork. Turn off the heat and puree the soup with an immersion blender until the soup is smooth and uniform. Ladle the soup into bowls and serve topped with sour cream, red onion and cilantro.