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