In a large pot, have 1/2 cup of the oil heated over high heat.
Cut some of the tortillas into 1-inch strips and set aside. Fry the tortilla strips in batches until golden brown on both sides, adding more oil as needed. Drain on paper towels.
Season the chicken with the cumin and salt and set aside.
Remove all but 2 tablespoons of oil from the pan. Add the onion, Essence and salt, and sauté until soft, about 3 minutes. Add the chicken, garlic, tomatoes and chiles and sauté for 3 minutes. Add the stock and lime juice and simmer over medium heat for 10 minutes.
Remove from the heat and stir in the cilantro.
Place 1 lime slice in each soup bowl and ladle the soup on top. Top each serving with diced avocado and serve the fried tortilla strips on the side.
Yield: 4 servings