Soak beans in water overnight. In large skillet over medium-low heat, cook onions in olive oil until nicely brown all over (this takes a while). Add garlic, and cook until carmelized (do not allow garlic to burn). Add Cajun seasoning and paprika, and cook for about another minute. Place drained beans, vegetables, tomato paste and chicken broth in slow cooker and cook on high until beans are soft. Add rice and allow rice to cook until done.