In a large saucepan, saute the garlic, carrot and celery in butter until tender.
Stir in flour until blended.
Gradually add broth.
Stir in rice, chicken, salt, pepper and rosemary.
Bring to a boil over medium heat.
Cook and stir for 2-3 minutes or until thickened.
Stir in milk and cook 2-3 minutes longer.