Heat oil in large skillet and carefully drop in half the tortilla strips. Fry in batches until golden brown and crunchy. Place fried tortilla strips on a paper towel-lined plate and pat dry. Sprinkle salt on tortillas, tossing to coat both sides.
Using a blender or food processor, blend tomatoes, onion and cilantro until completely pureed.
In a saucepan, heat chicken broth, chipotle chili, and pureed vegetables. Bring to a boil; remove from heat. Ladle soup into serving bowls. Prior to serving, add tortilla strips and avocado. Buen provecho!