Sauté garlic and onions in oil in large pan or Dutch oven until soft.
Add next 10 ingredients to pot, bring to a boil, reduce heat, and simmer 20 minutes.
Whisk flour/w ater mixture into soup.
Bring to a boil, reduce heat, and simmer for 5 minutes.
Add chicken and simmer for 5 minutes.
Add cream, sour cream, and cheese; stir until cheese is melted.
Deep-fry tortilla strips in 350 degree oil OR spray with non-stick cooking spray and bake in a 400 degree oven until crisp.
Sprinkle with salt if desired.
Pour soup into bowls, pile tortilla strips into a "haystack" shape on top of the soup, garnish with cilantro.