“Aztec soup” or “Aztec tortilla soup” (“sopa Azteca” in Spanish) is another name for “tortilla soup.” Mexico City is the probable origin for tortilla soup (“sopa de tortilla” in Spanish), and the city has many architectural remains of the Aztec civilization that flourished from 1300 to 1521.
   
“Sopa azteca” was printed in the book Especialidades de la Cocina Criolla (1958). “Aztec soup” from the Senor Pico restaurant in San Francisco, was printed in the Los Angeles (CA) Times on October 31, 1965. Aztec Soup, from San Angel Inn in Mexico City, was printed in the book A Snob’s Guide to Mexico City (1966) by Richard Magruder.
   
       
Google Books
Especialidades de la cocina criolla [las auténticas recetas de los platos nativos más característicos de toda la América Latina]
Buenos Aires, Argentina: Compañia General Fabril Editora,
1958
Pg. 46:
Sopa azteca
 
31 October 1965, Los Angeles (CA) Times, “Traveler’s Diary: Don’t Be a Tourist in S.F.” by Horace Sutton, sec. 1, pg. 9, cols. 6-7:
There is also a gorgeous restaurant called Senor Pico which dispenses tamales, rellenos, Aztec soup, and hot crab sandwiches.
     
Google Books
A Snob’s Guide to Mexico City
By Richard Magruder
Dallas, TX: Taylor
1966
Pg. 44:
The Inn’s Aztec Soup is another tour de force, but the single dish the staff itself seems to prefer is Ranch Style Chicken San Angel Inn—saucy, tender and succulent.
 
30 April 1967, Los Angeles (CA) Times, “Roundabout” by Lois Dwan, Calendar sec., pg. 38, col. 2:
These were followed by Aztec soup and fresh sea bass salsa, with Vera Cruzana.
       
14 November 1971, The Arizona Daily Star (Tucson, AZ), “Dorothy Gaines’ In and About Tucson,” sec. E, pg. 2, col. 1:
The lady (Emily Haugh—ed.) whom Governor Fannin some time ago officially declared “The Soup Queen of Arizona” had one tureen of a delectable seafood chowder and another of sopa Azteca; also cold roast beef, pate, and a great assortment of cheese and hot breads.
 
Google Books
Trader Vic’s Book of Mexican Cooking
By Victor Jules Bergeron and Cheryl Olsen
Garden City, NY: Doubleday
1973
Pg. 81:
Sopa Azteca
Aztec Soup
1/2 cup chopped onions
1/2 cup chopped okra
4 tablespoons butter
4 tablespoons chopped celery leaves
2 teaspoons crushed basil leaves
3 quarts chicken stock
1 tablespoon tomato paste
Salt and pepper to taste
1/2 cup sherry ...
   
24 January 1973, Tucson (AZ) Daily Citizen, “Tucson women give special soup recipes,” pg. 27, col. 2:
Sopa Azteca is Mrs. John Haugh’s easy and delicious rendition of a soup she enjoyed in Mexico City.
 
Be sure to add the tortilla chip crumbs and cheese cubes JUST before serving. The soup can be made in any amount.
 
SOPA AZTECA
(Mrs. John Haugh)
Equal parts tomato soup and consomme (She prefers Campbell’s.)
Diced green chiles, to taste
Corn tortilla chips, crumbled
Monterrey Jack cheese cubed
1. Bring soups and chiles to boil.
2. Just before serving, add tortilla chip crumbs and cheese cubes.
     
7 July 1974, Los Angeles (CA) Times, “Roundabout” by Lois Dwan, Calendar sec., pg. 68, col. 2:
Avocados of Senor Pico
Senor Pico accepted another challenge when it endeavored to prepare a lunch with avocados appearing in every dish. They managed and we managed. Guacamole and nachos McLaughlin were among the appetizers; sopa azteca added slivered tortilla, avocado pieces, pasilla chile to chicken stock; ...
 
Google Books
Frommer’s Mexico & Guatemala on $15 & $20 a Day
By Tom Brosnahan and Jane Kretchman
New York, NY: Arthur Frommer
1981
Pg. 185:
The Fonda is famous for its Aztec tortilla soup (30 pesos), and rightly so, as it makes a light meal in itself: meat, stock, tomatoes, cheese, tortillas, and slices of avocado are all in it. For gringoes, it’s served sin chiles (no hot peppers).
 
12 August 1982, Tampa (FL) Tribune, “Nothing Mickey Mouse About Mexican Menu” by Mary D. Scourtes, pg. 1E, col. 3:
A favorite at the original San Angel Inn, is soup, Sopa Azteca, made by cooking tomatoes, onions and herbs and chicken consomme and garnishing all with strips of fried corn tortillas and minced avocado. The soup for the luncheon was seasoned with a wild herb, epazote, also called unappetizingly “worm seed,” and the toasted chili pepper known as pasilla. Everyone raved about the spicy soup.
 
January 1983, Cosmopolitan (New York, NY), “Travel Bug” by Roberta Ashley, pg. 167, col. 1:
Try the lobster in garlic sauce, and at least split a plate of the heavenly Aztec tortilla soup with a friend.
 
18 February 1983, St. Petersburg (FL) Times, pg. 10D, col. 3:
(San Angel Inn.—ed.)
An order of sopa Azteca, a tortilla soup ($1.50), was an interesting and tasty blend of vegetable broth. it had strips of corn tortillas and chunks of tomato, plus one hot pepper.
   
11 December 1983, New York (NY) Times, “A Taste of Mexico in Perth Amboy” by Anne Semmes, pg. NJ45:
A fortifying and delicious soup, sopa Azteca, a tomato-based broth simmered with strips of tortillas, onions and spices and garnished with an enormous chile, would be adequate for a light winter’s supper. 
(Carvajal in Perth Amboy, NJ—ed.)
     
13 August 1986, New York (NY) Times, “The Place Where Real Texans Eat Soup” (El Mirador, San Antonio) by Peter Applebome, pg. C3:
The soup is sopa Azteca, and El Mirador is a modest stucco restaurant at the edge of downtown. It has been run by Mary and Julian Trevino and their family since 1967.
(...)
Sopa Azteca, the most popular offering, is a spicy tomato broth filled with chicken, spinach, avocado, peppers, potatoes, cheese, tortilla strips and other assorted spices and vegetables.
 
26 October 1986, Los Angeles (CA) Times, pt. 7, pg. 27, col. 2:
With a hi-fi going full blast, though, the decibels are easier to take in the hotel’s other restaurant, Las Olas, with its smoked salmon tacos, ceviche, Aztec-style tortilla soup, red snapper and carne asada tampiquena, which is to say beef tenderloin with guacamole, which is to say beef tenderloin with guacamole, rice and beans.
 
Google Groups: alt.gourmand
Cleartext copy of “Sopa Azteca (Aztec soup) “
Loretta Guarino Reid
4/8/88
SOUP-AZTEC(SP)        USENET Cookbook       SOUP-AZTEC(SP)
SOPA AZTECA
 
SOUP-AZTEC - Aztec soup: a simple cheese, tomato, and beef soup
 
I got this recipe from my mother, who got it from a friend in Tucson, Arizona.  The recipe is extremely simple and extremely quick. I like to serve it with Mexican chef’s salad (SALAD-MEXICAN).
 
INGREDIENTS (Serves 4-6)
2 cups   consomm’
2 cups   cream of tomato soup (use the recipe of your choice, or open a can)
4 oz     green chilies, diced (or use more or less, to taste)
1/4 lb   corn tortilla chips, crumbled
1/2 lb   Monterey Jack cheese, cut into half-inch (or smaller) cubes.
 
PROCEDURE
(1)  Mix soups and bring to a boil.
(2)  Fill each soup bowl about 1/3 full with crumbled tortilla chips.  Place a layer of cheese cubes on top of the chips. Put one or two spoonfuls of diced, drained chilies on top of the cheese.
(3)  When ready to serve, ladle boiling soup on top of the mixture in the soup bowls. Do not stir. Serve immediately.
   
18 May 1988, New York (NY) Times, “Chicago” by Dennis Ray Wheaton, pg. C3:
The Chon y Chano menu is impressive. For example, sopa Azteca, a central Mexican variation on a chicken and tortilla soup common across Mexico, is a chicken-tomato broth laced with fried tortilla strips, cheese, chili and lime. It is served with a large dried rd chili pod, roasted until it puffs and crumbled into the soup for added flavor, texture and heat.
   
5 November 1989, New York (NY) Times, “What’s Doing in San Antonio” by Lisa Belkin, pg. XX10:
Among the restaurants are El Mirador (722 South St. Mary’s Street; 512-225-9444), famous for Saturday soup, so named because it is served only from 11 A.M. to 3 P.M. on Saturday, where there is always a crowd. The most popular version, sopa Azteca, is loaded with chicken, white cheese, potatoes, avocado, spinach and strips of tortilla chips, among other things and will fill you up for $3.25 for a bowl. 
     
Google Books
The Book of Regional American Cooking
by Janeth Johnson Nix
HPBooks
1993
Pg. 28:
AZTEC SOUP
Vegetable oil for deep-frying
2 corn tortillas, cut into 1/8-inch strips
2 teaspoons vegetable oil
1/2 cup chopped onion
1/2 cup thinly sliced celery
2 garlic cloves, minced
1 teaspoon minced fresh jalapeno chile
1 (about 1-lb.) can tomatoes, undrained
4 cups regular-strength chicken broth
1 cup frozen whole-kernel corn
1 teaspoon ground cumin
1 cup shredded cooked chicken
1 tablespoon fresh lime juice (...)
 
Saveur
MEXICAN TORTILLA SOUP (SOPA AZTECA)
BY FARIDEH SADEGHIN AUGUST 31, 2015
(...)
Crunchy tortilla chips were divided between bowls, and the pasilla chile- and tomato-based broth was ladled over the top. Topped with avocado, cheese, and crema, this dish was perfection.
(...)
Ingredients
1 large pasilla chile
1 (15-oz.) can diced tomatoes
2 tbsp. canola oil
3 cloves garlic, peeled
1 medium white onion, roughly chopped
8 cups chicken stock
1 epazote or cilantro sprig (optional)
1 1⁄2 lb. boneless, skinless chicken breast, cut into 1⁄2-inch pieces
Kosher salt and freshly ground black pepper
6 oz. shredded Monterey Jack cheese
1-2 avocados, diced
Crema or sour cream, for serving
Lime wedges, for serving
Tortilla chips (about 4 cups), crushed, for serving