Dice celery, carrot and if using fresh, the onion. Melt butter in frying pan over medium heat and saute the vegetables for about 5 minutes.
Then add the flour and stir and cook for two more minutes
Add the milk and broth, slowly while stirring.
Simmer for a couple of minutes, then add the chicken, dried onion, instant rice and buffalo sauce.
Simmer for 5 minutes more, then add the cheese.
Stir it in and simmer about 5 more minutes. Taste and add salt and pepper as needed.
If you like, top with sour cream, and serve with celery sticks.