In a large pot, heat the olive oil over medium heat. Add the diced onion and cook for about 5 minutes, or until softened. Stir in the minced garlic and cook for an additional minute until fragrant.
Add the bell pepper, cumin, chili powder, smoked paprika, and cayenne pepper (if using) to the pot. Cook for another 3-4 minutes, stirring occasionally.
Pour in the diced tomatoes and chicken broth, then bring the mixture to a simmer.
Stir in the shredded chicken, black beans, and corn. Allow the soup to simmer for about 10-15 minutes, letting the flavors meld together.
Reduce the heat to low and slowly stir in the heavy cream. Season with salt and pepper to taste. Heat through but do not boil.
Serve the soup hot, topped with tortilla strips, diced avocado, and fresh cilantro. Squeeze lime juice over each bowl before enjoying.