Step 1: Sauté the Vegetables - Heat 2 tablespoons olive oil in a large pot over medium-high heat. Add the diced white onion and diced red bell pepper. Cook for about 5 minutes, stirring occasionally, until the vegetables begin to soften and the onion becomes translucent.

Step 2: Toast the Spices - Stir in the minced garlic, chili powder, paprika, and ground cumin. Cook for about 60 seconds, stirring constantly, until the spices become fragrant.

Step 3: Cook the Chicken - Pour in the 4 cups of chicken broth. Add the 3 boneless skinless chicken breasts to the pot. Bring the mixture to a boil, then reduce the heat to low. Cover and simmer for 15-20 minutes, or until the chicken is fully cooked through and reaches an internal temperature of 165°F (74°C).

Step 4: Shred the Chicken - Remove the cooked chicken breasts from the pot and place them on a cutting board. Using two forks, shred the chicken into bite-sized pieces. Return the shredded chicken to the pot.

Step 5: Add Remaining Ingredients - Stir in the fire-roasted diced tomatoes (with their juice), tomato sauce, drained black beans, undrained green chiles, and corn.

Step 6: Simmer and Season - Increase the heat to medium-high and bring the soup to a simmer. Let it simmer for about 5 minutes until everything is heated through and the flavors meld together beautifully.

Step 7: Finish with Fresh Ingredients - Remove from heat or just before serving, stir in the chopped fresh cilantro and lime juice. Season with salt and pepper to taste.

Step 8: Prepare Tortilla Strips (Optional) - Heat about 1 tablespoon vegetable oil in a skillet over medium-high heat until shimmering. Add one corn tortilla at a time and fry for about 30 seconds per side, until crispy and golden brown.

Step 9: Serve - Ladle the hot chicken tortilla soup into bowls. Top each serving with a dollop of sour cream, diced fresh avocado, shredded Monterey Jack cheese, and crispy tortilla strips.