Saute the onions and red bell peppers in 1 tbsp of olive oil in a pan on the stovetop over medium heat until golden brown. Set aside.
Combine the broth, pearled sorghum, green chiles, garlic and black beans in the slow cooker.  Cover and cook on HIGH for 1 hour. Add sauted onion and red bell pepper mixture into the slow cooker and cook for an additional hour. (cook 15 minutes longer if you prefer your sorghum to have a softer texture). Remove lid and fluff with a fork. Salt and pepper to taste.

In a bowl, combine the avocado, garlic, oil, lime juice and cilantro. Using a fork or wooden spoon, mash the avocado to your desired consistency. Add in tomatoes, salt and pepper to taste. Spoon sorghum mixture into bowls and top with a generous portion of the avocado sauce.