Heat the salsa in a large saucepan over medium heat, stirring frequently, for about 5 minutes.
Stir in the beans and broth, then heat to boiling. Reduce heat to low. Cover and simmer for 15 minutes.
Cool slightly, then spoon half the soup into a food processor or blender and puree.
Return the pureed soup to the saucepan and heat through. Stir in the sherry (if desired).
Serve with the sour cream, additional salsa, and lime wedges (if desired).