Heat olive oil in a large Dutch oven or stockpot over medium heat. Add diced onion and red bell pepper, cooking until softened, about 5-7 minutes. Add minced garlic and cook for another minute until fragrant.

Stir in the ranch seasoning mix, chili powder, ground cumin, smoked paprika, and cayenne pepper (if using). Cook for 1 minute, stirring constantly, to toast the spices.

Add the undrained diced tomatoes, rinsed black beans, drained corn, and chicken broth to the pot. Bring the mixture to a simmer, then reduce heat to low, cover, and let it cook for 15 minutes to allow the flavors to meld.

Stir in the shredded cooked chicken. Add the softened cream cheese in small dollops and stir until completely melted and incorporated into the soup. Pour in the heavy cream and stir well.

For a creamier texture, remove about 2 cups of the soup and carefully blend it in a regular blender until smooth (vent the lid carefully for hot liquids), or use an immersion blender directly in the pot to blend about one-third to half of the soup until desired creaminess is achieved. Return the blended portion to the pot if using a regular blender.

Continue to simmer for another 5-10 minutes, stirring occasionally, until the soup is heated through and slightly thickened. Taste and adjust seasonings as needed.

Ladle the hot soup into bowls. Garnish with tortilla strips, shredded cheese, fresh cilantro, diced avocado, and a squeeze of fresh lime juice, if desired. Serve immediately.