Start by roasting the dried ancho chilies in a dry skillet over medium heat for 2-3 minutes until fragrant and slightly blistered, releasing a smoky aroma.
Transfer the roasted chilies to a bowl and soak them in hot chicken broth for about 10 minutes until softened and pliable.
While the chilies soak, chop the onion and mince the garlic cloves, preparing them for sautéing.
In a blender, combine the softened chilies and soaking liquid, garlic, cumin, oregano, and a splash of chicken broth. Blend until the mixture is smooth and vibrant red, about 30 seconds.
Heat oil in a large pot over medium heat. Add chopped onions and cook until translucent and fragrant, about 5 minutes, stirring occasionally.
Pour the blended chili sauce into the pot with the onions. Cook for another 5 minutes, stirring often, until the mixture darkens slightly and releases a smoky aroma.
Add the shredded cooked chicken to the pot, stirring to coat it with the sauce.
Pour in the remaining chicken broth and bring the soup to a gentle simmer. Let it cook uncovered for about 20 minutes to meld the flavors and warm the chicken thoroughly.
Taste the broth and season with salt and lime juice to your liking, adjusting acidity and saltiness.
Turn off the heat and let the soup rest for 5 minutes so the flavors can settle and intensify.
Ladle the hot soup into bowls, garnish with chopped cilantro, and top with crispy tortilla strips for added texture.
