1 1/2 teaspoons olive oil
1/4 cup onion, chopped
3/4 teaspoon ground cumin seed
1/2 teaspoon oregano
1/8 teaspoon dried thyme
1 pound canned black beans, drained
1 cup crushed tomatoes
3/4 cup beef stock or  beef flavored broth powder
1/4 cup salsa
2 tablespoons light sour cream
2 tablespoons scallions, finely chopped

Heat oil in a heavy saucepan over medium high heat. Sauté onion 4-5 minutes or until onion turns golden. Stir in next three ingredients and sauté one minute, stirring constantly.

Transfer to a food processor or blender. Add next four ingredients and purée until mixture is smooth. Return mixture to pan and simmer over low heat 20 minutes, stirring frequently.

Serve soup with a dollop of sour cream and sprinkled with scallions.