My favorite ingredient in the tortilla soup is the ancho chile. Ancho Chiles are red poblano chiles that have been dried.
Prepare the Ancho Chiles and Tomatoes:
In a Pyrex® bowl, pour boiling water over the Ancho Chiles, set aside for about ten minutes. Remove chiles from water and discard the stems and seeds. Place the softened Ancho Chiles in the bowl of a food processor. Puree until smooth. Add the canned tomatoes and roasted tomatoes pulse until the tomatoes are bite-size. Set aside.
In a heavy bottomed, 4-quart saucepan set over medium heat, heat 2 tablespoons olive oil. Add the onion and red pepper, sauté for 5 minutes. Add the garlic and sauté for another minute.
Stir in chili powder and cumin, cook for 1 minute.
Add the prepared Ancho Chiles and Tomatoes, chicken stock and corn. Simmer for about 1 hour. Add the cooked chicken, simmer for 10 minutes. Season to taste with salt and pepper.
Setting the buffet:
Arrange the garnishes in small bowls, wide-rimmed soup bowls, spoons on a buffet table alongside the simmering soup.
Ladle Tortilla Soup into soup bowls and garnish with favorite toppings.