You can't go wrong with risotto, or roasted butternut squash for that matter, but to make this recipe extra special, I gave the squash a sugary treatment and fired all decadent engines with the risotto. It's not exactly diet-friendly, but boy is it good.
Preheat the oven to 425 degrees.
On a nonstick baking sheet, toss the butternut squash, olive oil, and brown sugar together. Season with salt and pepper, to taste. Roast in the oven until the squash is golden brown and crispy, about 30 minutes.
Meanwhile, combine the chicken stock and water in a small saucepan and place over low heat. Melt the butter in a large sauté pan over medium-high heat. Add the onion and thyme, season with salt and pepper, to taste, and cook until the onion is translucent, about 5 minutes. Add the arborio rice to the pan and stir well so that each grain is coated in butter. Reduce the heat to medium-low and cook for 1 more minute to give the rice a nice toast, and then add the white wine and stir.
When the wine is completely reduced, add a ladleful of the water/chicken stock mixture to the pan. You want to add enough liquid so that the rice is completely covered when it is smoothed out evenly in the pan. Let the rice cook in the liquid, stirring once or twice, until the liquid is completely absorbed by the rice. Check to adjust the heat so that the pan does not scorch the rice during this process. When the rice is dry, add another ladleful of the liquid to the pan and repeat the process again until all of the liquid is gone and the rice is cooked through.
Midway through the last ladleful, add the roasted butternut squash to the risotto. (It's OK if the squash has become soft and is coming apart from roasting, because it'll incorporate into the risotto much better that way.) When the liquid is fully dissolved, add the heavy cream and Parmesan, stir, and serve.