Heat the butter in a large stock pot over medium-low heat. Add in the onion, carrots, celery, and garlic with a pinch of salt and pepper. Cook until the vegetables soften.

Stir in the garlic cloves and poultry seasoning, then add in the shredded chicken.

Add the chicken stock and the parmesan rind. Bring to a boil, then reduce to a simmer.

Stir in the orzo pasta and cook uncovered, stirring occasionally, until the orzo is al dente, about 8 minutes.

In a shaker bottle or bowl, shake (or whisk) together the milk and flour to form a slurry. Pour into the soup and simmer for another 1 to 2 minutes.

Taste and season with more salt and pepper if needed. If the parmesan rind didn’t melt entirely, scoop it out.

Stir in the fresh parsley and serve immediately with lemon wedges for spritzing and parmesan cheese for topping.