Heat oil in a dutch oven or medium size saucepan, over a medium heat. Add the onions and cook 4 minutes, stirring frequently. Add the garlic and cook another 1 minute.
Stir in the chicken broth, diced tomatoes, enchilada sauce, green chilies, and chicken. Bring to a boil, then reduce heat to low and simmer, uncovered, for 20 minutes.
Stir in the beans and corn and simmer another 15 minutes. Remove from the heat and stir in the sour cream and cheese.
When ready to serve, warm soup over a low heat. Ladle into a bowl and top with sour cream, cheese, and tortilla chips.
Notes
NUTRITIONAL DISCLAIMER. Calorie count provided is an estimate and will vary based on cooking methods and brands of ingredients used.