In a large pot heat the oil over medium high heat and add the onion. Sauté until softened, about 5-6 min. Add the garlic, chipotles and cumin cooking until fragrant, 2-4 min.

Add the sweet potatoes, broth, water, salt and pepper and bring to a boil . Reduce the heat to medium low and simmer.

Cover and cook 20 minutes until sweet potatoes are tender.

Using an immersion blender, food processor, or stand blender puree the soup until smooth. Add the yogurt and continue to puree until it is all incorporated.

Ladle the soup into bowls and top with a dollop of yogurt and garnish with cilantro.