In your large pot, melt the 2 tablespoons of butter over medium heat. Add the diced onion and minced garlic, sautéing until the onion becomes translucent and fragrant, about 3-5 minutes.
Next, stir in the diced celery and diced carrots. Cook for an additional 5 minutes, allowing the vegetables to soften slightly.
Add the diced green chiles to the pot, stirring to combine. Let them cook with the other ingredients for about 2 minutes, enhancing the flavor profile.
Pour in the 6 cups of chicken broth and bring the mixture to a simmer.
Add the chili powder, ground cumin, salt, and black pepper to taste. Stir well to incorporate all the seasonings.
Once the soup is simmering, stir in the frozen sweet corn and shredded chicken. Allow the soup to simmer for an additional 10 minutes.
In a small bowl, whisk together the all-purpose flour and heavy cream until smooth. Gradually add this mixture to the soup while stirring to avoid lumps. Continue to simmer for another 5-10 minutes until the soup thickens.
Ladle the creamy soup into bowls and top with freshly grated cheddar cheese, a dollop of sour cream, chopped cilantro, broken tortilla chips, and diced green onions for added flavor and texture.