Heat vegetable oil in a large pot over medium-high heat. Add diced chicken and cook for 5-6 minutes until browned and cooked through. Remove and set aside.
In the same pot, add onion and bell pepper. Sauté for 4-5 minutes until softened. Add garlic and cook for 1 minute more.
Add chicken broth, diced tomatoes with green chilies, black beans, and corn. Stir to combine.
Stir in chili powder, cumin, paprika, salt, and pepper. Bring to a boil, then reduce heat and simmer for 15 minutes.
Add the cooked chicken back to the pot along with the cream of chicken soup. Stir well to incorporate.
Add cubed Velveeta cheese and stir until completely melted and the soup is creamy and smooth.
Simmer for an additional 10 minutes, stirring occasionally. Taste and adjust seasoning as needed.
Serve hot, topped with crispy tortilla strips, shredded cheese, sour cream, and fresh cilantro if desired.