In a large saucepan, heat the oil over medium heat. Add the carrot, corn and onion and cook until the vegetables being to soften, about 8 minutes. Season with salt.
Add the garlic, chile powder and cumin and cook until the spices are fragrant, about 1 minute. Add the beans, chipotle and adobo sauce and stir just to combine. Pour in the stock and 1 cup water. Bring to a simmer and cook until thick and creamy, 35 to 40 minutes.
Stir in the lime juice and season with salt, if necessary. Puree the hot soup with a hand blender, if desired, or leave chunky. Serve in soup bowls with the cilantro and a dollop of sour cream.