Tortilla Soup with Pasilla Chile, Fresh Cheese and Avocado

FRYING THE TORTILLAS. Cut the tortillas in half, then into 1/4-inch strips. In a medium-large (4-quart) saucepan, heat the 1/2 inch of oil over medium to 350 degrees F. (Using a thermometer is most accurate, but there are other reliable clues: the oil releases that "hot oil" aroma and its surface begins shimmering. Without a thermometer, test the edge of a tortilla strip to insure that it sizzles vigorously. Remember smoking oil is dangerously overheated and will give the tortilla strips a bad taste.) Add half the tortilla strips. Stir around in the oil nearly constantly until they are golden-brown and crispy. With the slotted spoon, scoop them out and drain on paper towels. Repeat with the remaining tortillas.

OTHER PRELIMINARIES. Pour off all but a thin coating of hot oil in the saucepan and return to the heat. Add the garlic and onion to the oil and cook, stirring regularly, until golden, about 7 minutes. Use a slotted spoon to scoop out the garlic and onion, pressing them against the side of the pan to leave behind as much oil as possible. Transfer garlic and onion to a blender or food processor. Add the chile pieces to the hot pan. Turn quickly as they fry, toast and release a delicious aroma - about 30 seconds in all. Too much frying/toasting will make them bitter. Remove and drain on paper towels. Set the pan aside.

THE BROTH. Add the tomatoes to the blender containing the garlic and onion, and process to a smooth puree. (If using fresh tomatoes, strain the puree to get rid of the pieces of tomato skin.) Set the saucepan over medium-high heat. When hot, add the puree and stir nearly constantly until it has thickened to the consistency of tomato paste, about 10 minutes. Add the broth and epazote, bring to a boil, then partially cover and gently simmer over medium to medium-low heat for 30 minutes. Taste and season with salt, usually 1/2 teaspoon depending on the saltiness of your broth.

SERVING THE SOUP. When you're ready to serve, divide the cheese and avocado among the soup bowls. Ladle a portion of the broth into each bowl, top with a portion of the tortilla strips and crumble on a little toasted chile. Carry these satisfying bowls of soup to the table and offer your guests wedges of lime to squeeze in to their liking.

WORKING AHEAD: Steps 2 and 3 can be completed several days ahead (which means you'll have the soup virtually ready to serve). The tortilla strips (Step I) will begin to taste stale if not fried the day they're served. Store made-ahead soup in the refrigerator, covered.