Tortilla Soup with Chiles and Tomatoes

Ingredients

• 6 ounces avocado cut into 1/2-inch pieces
• 2  chiles de á:rbol dried stemmed
• 4  pasilla chiles dried stemmed seeded
• 144 servings corn tortillas cut into 1-inch squares (6-to )
• 0.3 cup crema sour with 1 tablespoon water diluted
• 1 teaspoon epazote leaves dried crumbled
• 2 large garlic cloves chopped
• 4 servings accompaniment: lime wedges 
• 2 ounces ricotta salata crumbled (also called queso añejo)
• 0.5 pound tomatoes quartered
• 3 cups vegetable oil for frying
• 1 large onion white coarsely chopped

Equipment

• bowl
• frying pan
• paper towels
• ladle
• oven
• pot
• blender
• slotted spoon
• tongs

Directions

1. Toast chiles in a dry heavy skillet (not nonstick) over medium-high heat, turning with tongs, until pliable and slightly changed in color, about 30 seconds. Coarsely crumble 1 pasilla chile and set aside.
2. Purée tomatoes, onion, garlic, chiles de á:rbol (including seeds), and remaining 3 pasilla chiles with 1/2 cup stock in a blender.
3. Heat lard in a large heavy pot over medium heat until it shimmers, then cook purée, stirring frequently, until reduced by half and beginning to stick to pot, 15 to 20 minutes. Stir in remaining 7 1/2 cups stock, epazote, and 1 teaspoon salt, then simmer, uncovered, 45 minutes.
4. While soup simmers, heat 1 inch oil to 350°F in a deep 10-inch heavy skillet, then fry tortilla squares, a handful at a time, until golden, 30 to 45 seconds per batch.
5. Transfer with a slotted spoon to paper towels to drain and season lightly with salt.
6. Divide tortillas and avocado among soup bowls and ladle in soup.
7. Sprinkle with cheese, drizzle with crema, and top with crumbled chile.
8. •Soup can be made 3 days ahead and chilled (covered once cool). •Tortillas can be fried 1 day ahead and kept in an airtight container. Rewarm in oven.•You can use unsalted store-bought tortilla chips in place of homemade.