In a large saucepan or Dutch oven heat the canola oil over medium heat. Add the onion, garlic, cumin, and chili powder. Saute for about 3 to 4 minutes, until onion is tender.
In a bowl, combine 2 cans of the black beans with the chicken broth; puree in the blender in batches.
Add the pureed beans to the onion mixture. Stir in the remaining can of beans, lime juice, the salsa, and green chile peppers. Add hot sauce, to taste. Bring to a boil; reduce heat to low and simmer for 30 minutes.
Ladle into bowls and top with a dollop of sour cream, if desired, along with shredded cheese and chopped green onions or diced tomatoes.
Calories per serving: 277