Rinse beans. Place beans in a large saucepan or Dutch oven. Add enough water to cover by 2 inches. Bring to boiling; reduce heat. Simmer, uncovered, for 10 minutes. Remove from heat. Cover; let stand for 1 hour.
Meanwhile, in a large skillet heat oil over medium-high heat. Add half of the meat and the onion; cook and stir until meat is browned. Transfer to a 3-1/2- or 4-quart slow cooker using a slotted spoon. Repeat with remaining meat. Stir tomato sauce, tomatoes, broth, chipotle peppers and adobo sauce, oregano, and cumin into mixture in slow cooker. Drain and rinse the beans; stir into mixture in cooker.
Cover and cook on low-heat setting for 10 to 12 hours or on high-heat setting for 5 to 6 hours. If desired, top individual servings with sweet pepper and cilantro.