Prepare the chicken by seasoning it with kosher salt and black pepper, placing it at the bottom of the slow cooker.

Combine the chicken stock, wild rice, minced garlic, diced onion, sliced carrots, and chopped celery in the slow cooker. Add dried thyme, rosemary, and bay leaves, then stir.

Cover and cook on low for 6 to 8 hours. Add cremini mushrooms about 30 minutes before the cooking time ends.

Once cooked, shred the chicken into bite-sized pieces and return it to the soup.

Melt unsalted butter in a saucepan, whisk in flour, then gradually add milk and half and half, cooking until thickened.

Pour the thickened mixture into the slow cooker and stir to blend.

Ladle into bowls and garnish with fresh parsley before serving.