Season chicken with salt and pepper, to taste. Place chicken into a 6-qt crock pot.
Stir in chicken broth, wild rice, garlic, onion, carrots, celery, thyme, rosemary and bay leaves; season with salt and pepper, to taste. Cover and cook on low heat for 6-8 hours. Or on high for 4 hours.
Remove chicken from crock pot and shred.
Melt butter in a saucepan over medium heat. Whisk in flour until lightly browned, about 30 seconds. Whisk in milk and half and half, whisking constantly, until slightly thickened, about 5 minutes.
Stir chicken and milk mixture into the crock pot. If the soup is too thick, add more milk as needed.
Serve warm, garnished with parsley.