Heat the olive oil in a large pot over medium heat.
Add the diced onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and diced bell pepper; cook for another 3-4 minutes.
Add the can of diced tomatoes, chicken broth, shredded chicken, cumin, chili powder, and salt and pepper.
Bring the mixture to a boil, then reduce the heat and let it simmer for 30 minutes.
Stir in the lime juice just before serving.
Prepare tortilla strips by frying or baking until crispy.
Serve the soup hot, topped with tortilla strips and chopped cilantro.