In a Dutch oven or large heavy pot, heat the oil on medium-high heat. Add the onions, garlic, peppers, salt, cumin, and coriander for 5 minutes. Add the tomato paste and cook, stirring, for 1 minute. Add the chicken stock and bring to a simmer. Simmer for 20 minutes. Add the chicken and simmer for 5 minutes. Add the cilantro and lime juice, and stir well. Remove from the heat and cover to keep warm.
Heat the oil in a heavy pot or electric fryer to 350 degrees F. Add the tortilla strips in batches and fry until golden and crisp, 1 1/2 to 2 minutes. Remove with a slotted spoon and drain on paper towels. Season with the Essence.
Ladle the soup into 4 or 6 serving bowls. Garnish each serving with the diced avocado, the fried tortilla strips, and Chipotle Crema.
Yield: 4 to 6 servings