Heat a large soup pot over medium-high heat. Add olive oil and unsalted butter. Once melted, add the chopped onion, celery, and carrots. Sauté for about 5-7 minutes until the vegetables are soft.
Add the garlic and sprinkle the flour, onion powder, dried dill, and ranch seasoning over the sautéed vegetables. Stir for 1 minute. Pour in the chicken broth and buffalo wing sauce.
Add the chicken breasts to the pot. Increase the heat to bring the mixture to a boil, then reduce to a simmer and cook for 10-15 minutes until the chicken is fully cooked.
Season with salt and pepper, then simmer for an additional 3 minutes. Serve hot, with chopped green onions and blue cheese crumbles as optional garnishes.