Sauté your chicken, celery, onion, garlic and mushrooms in butter. Salt and pepper to taste.
While chicken and veggies cook, Bring 2 cups of stock to a boil. Gently stir barley into boiling stock. Cook according to package directions, about 10 minutes.
Add 3 cups stock, cooked barley and sautéed ingredients to a large saucepan.
Slowly stir in milk.
Heat thoroughly and serve.
