Step 1

Put the chicken broth in a medium saucepan and bring to a simmer over moderate heat, reduce heat to moderately low and continue to simmer gently.

Step 2

Heat the olive oil in a medium heavy pot over moderate heat. Add the onion and cook until translucent and softened, about 5 minutes. Add the squash, cover and cook, stirring occasionally, until the squash begins to soften, about 10 minutes.

Step 3

Add the rice and stir to coat with the oil and juices. Stir in the vermouth and cook, stirring, until evaporated.

Step 4

Begin to add the hot broth, 1 cup at a time, stirring until the broth has been absorbed. Continue adding the broth, 1 cup at a time, until the rice is plump and tender, but still slightly soupy.

Step 5

Add the cheese and stir until melted. Season to taste with salt and pepper. Spoon the risotto into warm bowls, top with chives and serve immediately.