Roast a medium-sized butternut squash  in the oven (375 degrees for 60-80 minutes). Peel and chop into small 1/2 inch pieces and place into a large saucepan with the chicken stock. Bring to a boil and then reduce to a simmer. 

In a large pot over medium-high heat, place the olive oil, chopped onion, salt, and sugar until the onions start to caramelize. Add the rice to the pot and let it absorb the oil for about 3-5 minutes. Add in the white wine and stir until incorporated.

Add the butternut squash chicken broth to the rice one ladle at a time. After the rice has absorbed the previous liquid, add the next ladle-full until the Squash/broth mixture has all been used. This should take approximately 20-25 minutes. 

Once all the broth has been added, and the rice has a creamy consistency, add in the rosemary and butter. Once the butter has melted, slowly add the Parmesan and stir until completely melted. Add additional salt to taste.