Add chopped onion and bell pepper, tomatoes, tomatoes and green chilies, chicken broth, tomato paste, and chipotle pepper in adobo.
Mix well to combine, place the lid on the slow cooker and set heat on low for 8 hours.
Remove cooked chicken from the cooker and allow to cool.
Then, use two forks or your fingers to shred it into bite-sized pieces.
Add chicken back to pot, along with sliced corn tortillas.
Cook another 10 minutes.
In a large skillet, heat canola oil over medium-high heat and fry tortilla strips until lightly browned around the edges, about 45 seconds. Transfer to paper towels to drain. Or you can use bagged chips.
When soup is ready to serve, stir in lime juice.
Season to taste with additional salt or pepper, if needed.
Ladle into bowls, and top with a handful of tortilla strips.
Each person can add avocados, a squeeze of lime juice, cheese, and cilantro according to taste.