1In 2-quart saucepan, mash beans slightly with potato masher. Stir in water, tomatoes, chipotle salsa and cumin. Heat to boiling over high heat; reduce heat. Cover; simmer 8 minutes, stirring occasionally. Uncover; simmer 2 minutes longer or until soup is slightly thickened.
2Meanwhile, in small bowl, gently toss avocado, lime peel, lime juice, cilantro and salt.
3Ladle 1 cup soup into each of 4 bowls. Top each serving with 1/4 cup avocado salsa. Garnish with sour cream.