Heat oil in Dutch oven, add onions, cumin and oregano. Saute 4 to 5 minutes. Stir in garlic and saute 1 to 2 minutes. Add cayenne, green chilies, broth and chicken base and bring to a boil. Reduce heat; add chicken and the cannellini beans. Simmer 10 minutes. Stir in sour cream and cheese, stirring until cheese melts.Serve with optional garnishes.
Optional Garnishes: chopped green onions fresh cilantro leaves lime wedges diced Roma or grape tomatoes chopped fresh serrano chilies