2. Meanwhile, place the barley in a fine strainer and rinse under cold running water to remove any residue of the bitter husks. Drain thoroughly.
3. In a small saucepan, bring the stock or water to a boil and add the turmeric. Keep the seasoned stock hot over low heat.
4. Heat the olive oil in a large, non-stick skillet over medium heat. Add the garlic and onion and cook until tender, about 5 minutes. Add the mushrooms and cook until tender and slightly browned, about 10 minutes. Add the barley cooking until the grains are hot, about 3 minutes.
5. Add 1 cup of hot stock and cook until just about all of the liquid has been absorbed. Season lightly with salt and pepper. Continue to add the stock 1 cup at a time, letting the barley absorb the stock before adding more. The barley is cooked when the grains are al dente, tender yet still with a resilient bite, about 20 to 25 minutes total.
6. Stir in the squash chunks just to reheat without crushing. Remove from the heat. Stir in half of the chives and Parmesan cheese. Adjust the seasonings one last time as necessary.
7. Spoon the risotto into warm rimmed soup plates. Garnish with the remaining chives and Parmesan cheese.