Heat the oil in a 3-quart saucepan over medium-high heat. Add the chicken and chili powder and cook until the chicken is well browned, stirring often.
Stir the soup, water and soup mix in the saucepan and heat to a boil. Reduce the heat to low. Cover and cook for 10 minutes.
Stir in the beans and cook until the mixture is hot and bubbling. Serve with the cheese and onions.