Bring 1 quart stock plus 1 cup water to a simmer in a sauce pot then reduce heat to low. Heat a medium skillet over medium to medium-high heat with olive oil. When oil ripples, add the onions and garlic and soften 2 to 3 minutes. Add rice and toast 2 to 3 minutes more. Add wine and cook it out completely, stirring occasionally, 2 to 3 minutes.
Ladle in stock in intervals, a couple of ladles at a time. Allow liquids to evaporate each time. Risotto will cook 18 minutes, total, from the first addition of liquid. Defrost the squash in your microwave in a dish to collect any liquids and stir in squash the last 3 minutes of cook time, season with nutmeg, salt and pepper to taste. In the last minute of cooking time, stir in butter in small pieces, sage leaves and cheese. Serve immediately.
This is Rachael Ray's recipe and I highly recommend this. It makes a large portion, so if you are cooking for two, halving the recipe will yield about four servings. The only ingredient I did not use was fresh sage.