1. In a saucepan bring broth and water to a simmer.
2. Add diced butternut squash and blanch until al dente.
3. In another saucepan cook onions, peppers, and garlic in butter over moderately low heat, stirring, until softened.
4. Stir in rice and cook over moderate heat, stirring constantly, about 1 minute.
5. Add wine and cook, stirring, until absorbed.
6. Stir in 1/4 cup broth and cook, stirring constantly, and keeping at a simmer throughout, until absorbed.
7. Continue simmering and adding broth, about 1/4 cup at a time, stirring constantly and letting each addition be absorbed before adding next, until about half of broth has been added.
8. Stir in diced squash and continue simmering and adding broth in same manner until rice is tender and creamy-looking but still al dente, about 18 minutes.
9. Stir in green onions and salt and pepper to taste.