Heat oil in a large saucepan over medium-high heat until hot.Add bell pepper, onion, and garlic; sauté 5 minutes or until tender. Stir in beans and next 4 ingredients; bring to a boil. Cover, reduce heat, and simmer 30 minutes.
. While black bean mixture cooks, cook rice according to package directions, adding turmeric to cooking water and omitting salt and fat. Drain rice.
. Spoon rice evenly onto serving plates, and top with black bean mixture. Serve with sour cream, and, if desired, garnish with cilantro.