Unheard of in this country until soldiers brought it back from Italy in WWII, oregano now lends its flavor to chili hailing from the Lone Star state.
Sort and wash beans; place in a large Dutch oven. Cover with water 2 inches above beans; let soak 8 hours. Drain beans, and return to Dutch oven. Add 3 cans chicken broth, chopped onion, and next 5 ingredients. Bring to a boil; cover, reduce heat, and simmer 2 hours or until beans are tender.
Add remaining can of chicken broth, chicken, and next 4 ingredients. Bring to a boil; cover, reduce heat, and simmer 1 hour, stirring occasionally. Serve with cheese, salsa, sour cream, and green onions.