Sweet Potato and Chipotle Soup

Courtesy of Martha Stewart (.com)

2T Olive oil
1 medium white onion
Coarse salt and black pepper
2t ground cumin
2 garlic cloves, minced
2t ground cumin
4-5 sweet potatoes (2 lbs total), peeled and cut
1 chipotle chile in adobo, chopped
7 cups low-sodium chicken broth
Sour cream, for serving

1. In a large Dutch oven or heavy pot, heat 1 T oil over medium high heat. Add onion, season with salt and pepper, and cook until beginning to brown around edges, about 7 minutes. Add cumin and garlic and cook, stirring, until fragrant, about 1 minute. Stir in sweet potatoes, chile, and broth. Bring to a boil; reduce to a rapid simmer, partially cover, and cook until sweet potatoes can be mashed easily with a spoon, 20-25 minutes.

2. Let soup cool slightly. Working in batches, transfer soup to a blender and puree until smooth (use caution when blending hot liquids). Return pureed soup to pot over low heat and season with salt and pepper. Top soup with sour cream, if desired.