Peel, deseed, and dice the butternut squash. Add it to a pot of boiling water and boil for 6-8 minutes until tender. Drain, and set the squash aside.
In a large pot, bring the vegetable broth to a boil, then lower heat to simmer.
Dice the onion and sage leaves. In a large saucepan, heat the olive oil, then add onion. Cook 1 minute, stirring frequently. Sprinkle onion with sugar and cook 2-3 minutes more until browned. Add sage and cook 1 more minute over medium heat.
Pour a bit more oil into the pan if needed. Push the onion-sage mix to the side and add the rice to the empty side, stirring constantly until browned (about 1 minute).
Now, add the wine to the rice, and stir until it is absorbed.
Gradually, one spoonful or ladle full at a time (about half cup at a time), add the vegetable broth, stirring until each half cup is absorbed by the rice. Once the rice absorbs the liquid, add another 1/2 cup. You should stir it frequently but if you need to step away for a bit you can. Just don't step away too long or the rice can stick.
Continue adding liquid to the rice and onion sage mixture, stirring frequently. Keep the mix over low-medium heat and uncovered. It will take about 30-40 minutes to absorb all of the liquid and cook the rice. If you need more liquid, heat water to boiling in a kettle and add it a little at a time. Taste the rice to make sure it is tender and creamy.
When rice is tender and creamy, stir in the butternut squash you had set aside. Heat on low for 1 minute longer. Add salt and pepper, or just pepper, to taste.
Serve warm as is for a vegan dish or add Parmesan cheese if desired.
Notes
Fresh sage adds wonderful taste to this dish but if you don't have fresh sage, substitute 1 tablespoon of dried sage.