Sort and wash beans; place beans in a large Dutch oven. Cover with water to a depth of 2 inches above beans. Bring to a boil; cover, remove from heat, and let stand for 1 hour. Drain beans, and return to Dutch oven. Add chicken broth; bring to a boil. Cover, reduce heat, and simmer 1 hour or until beans are tender. Remove 1/4 cup cooked beans, and mash with a fork. Return mashed beans to Dutch oven.
Coat a large nonstick skillet with cooking spray; add oil. Place over medium-high heat until hot; add chopped onion, sliced green onions, and garlic; sauté until tender. Add chicken; cook until chicken is no longer pink, stirring until it crumbles. Add chicken mixture to beans in Dutch oven; stir well. Add corn and next 4 ingredients; bring to a boil. Reduce heat, and simmer, uncovered, 20 minutes. Sprinkle cornmeal over chili; cook until thickened, stirring often. To serve, ladle into individual bowls, and top with chopped green onions, if desired.