1. Heat olive oil in large pot over medium-high heat. Sauti the onion for 2 minutes. Add garlic and tomatoes; sauti 2 minutes. Stir often.

2. Add beans, potatoes, and water. Bring to boil; then reduce to low-medium heat. Cook slowly, cover for 20 minutes.

3. Add cilantro, cumin, lime and hot sauce. Stir well and cook 10 minutes. Hot sauce to taste.

4. Serve hot and garnish with cilantro and sour cream.