1Heat a large dutch oven over medium-high heat. Add the chicken thighs, one onion half, three garlic cloves, and one jalapeño half. Pour in the broth and bring to a simmer. Cook for 25 minutes until the chicken is cooked through.
2Remove the chicken and set aside to cool slightly. Strain the broth, discarding the solids, and return it to the pot.
3Dice the remaining onion and mince the remaining garlic and jalapeño. Heat the oil in a separate skillet over medium heat. Sauté the diced onion, garlic, and jalapeño for 2 minutes until fragrant.
4Add the cumin and chili powder to the skillet and cook for 1 minute. Pour in the diced tomatoes with their juice and cook for 5 minutes.
5Transfer the tomato mixture to the pot with the broth. Shred the cooled chicken and add it back in. Season with salt and pepper. Simmer for 10 minutes.
6While the soup finishes simmering, cut the tortillas into strips. Heat oil in a small skillet and fry the tortilla strips in batches until golden and crispy, about 2 minutes. Drain on paper towels.
7Squeeze the lime juice into the soup and taste for seasoning. Ladle into bowls and top each serving with tortilla strips, avocado slices, cilantro, and queso fresco.