Sautee onion in a wide pot. Add chicken and enchilada sauce and stir until chicken turns white, adding water or chicken stock as needed. Pour the remainder of the liquid into the pot and salt to season.

Bring to a boil and add corn.

When the corn is tender, add sour cream and grated cheese.

Before serving, put corn chips in the bowls, pour soup over and garnish with chopped cilantro leaves and avocado slices.